Mechanics and Mechatronics (ICMM2015)

The following sections are included:

• Editorial Recent Research and Development on Mechanics and Mechatronics
• Contents

Fracturing technology is the core technology to develop unconventional resources especially low and extra low-permeability gas reservoirs, but the quality of fracturing ball determine the technical success or failure. The high performance PEEK/Carbon Fiber (CF) composite was prepared by means of extrusion pelletization with the raw material of Carbon Fiber and pure PEEK, and the micro-morphology, thermal performance and mechanics property of the composite were studied using infrared spectrum analysis, SEM, TGA test and laboratory testing. The results indicated that the combination of CF and PEEK was tight, the thermal decomposition temperature is above 500°C. when the mass fraction of CF was about 20%, and the tensile strength, shear strength and flexural strength of the composite were very good.

Aimed at investigating the quantitative relationship between different angles at which conical picks wedge rock and rock interaction, the cutting force in order to allow conical picks to work on rocks with a greater efficiency and lower energy consumption, this paper presents an analysis of the stress state of conical pick, based on the mechanics model of conical pick cutting rock and combined with actual working conditions in which conical picks work on rocks at different wedge angles. The paper introduces the determination of the stress distribution of conical pick cutting rock at different wedge angles, development of the cutting force mathematical model, the description of the law governing wedge angle and half cone angle on the effect of cutting force and changing trend and regularity, and the simulation. The results indicate that, where sum of the wedge angle and half cone angle is less than ninety degrees, cutting force assumes nonlinear variation characteristics.The cutting mechanics model marked by a greater reliability and the more simple mathematical description promises as a theoretical basis for cutting theoretical research and shearer design.

Aimed at a better evaluation of the performance of pick cutting, this paper, based on the experimental curve from the pick-shaped cutting resistance, introduces the application of the method of power spectrum to an qualitatively analysis of the chaotic characteristics, as when the shear is in the state of cutting, presents the relationship between chaos fractal dimension calculated from the sequence of cutting resistance and the yardstick of box dimension and introduces the use of MATLAB to the quantitative calculation of the box dimensions of the cutting resistance's time-series corresponding with the different installation angles of the cutting picks. The result shows that the cutting picks installed at 45-degree angle give the box dimension. The box dimensions and empirical mode decomposition, as described in the paper provide a new method for the theoretical research and design of drum shearers.

To ensure the safe use of hydraulic forward type positioner for processing and manufacturing railway vehicles, this paper analyzes the use working conditions of hydraulic forward type positioner and makes a contact nonlinear finite element analysis on typical working conditions. Based on the results of static strength analysis, positions of parts subject to danger and weakness procedures are found out; prejudging of the failure trend of parts is made. And the analysis provides guidance for prejudging the faults in actual production and can prevent occurrence of accidents.

In this paper, the effect of acceleration on the airflow level posture sensor is explained using a finite element model with the temperature field and the stream field monitored by the sensor as independent variable. By using the finite element method, the temperature field and the stream field in sensing element has been obtained. The results are as follow: (1) The temperature field and the stream field in sensing element deform under the effect of acceleration. (2) The velocity difference of airflow at two point heat sources changes with the acceleration, with the increase in acceleration, the airflow rate difference of two detecting hot wires decreases, difference of current through the thermal resistance wire is increased, the bridge outputs a voltage signal corresponding to the acceleration. (3) Effect of acceleration on the airflow level posture sensor is similar to the solid and liquid pendulum tilt angle sensor, when the acceleration inputs, the sensor can't tell acceleration signal and angle signal. In dynamic use, the interference of acceleration on airflow level posture sensor must be suppressed in order to ensure the use of the precision.

The paper determines the optimal position of thermistors in sensitive components of gas pendulum omnibearing level posture sensor is d=900 μm (d is distance of two relatively detection thermistors). By using the finite element method, through the establishment of three-dimensional modeling of the thermistors of sensitive element in different positions, different tilting states, the distribution of temperature field and flow field inside the sensitive element are calculated. The results show that: (1) When the d is changed, the temperature field and flow field changes. (2) The relation curve, which is about the difference Δv of airflow velocity around the two relatively detection thermistors and tilt angle, changes with the d. This opens the effective approaches for the optimization design of the sensor.

The squeeze-film damping in MEMS devices can be controlled by providing perforations in microstructures. Recently, there are many analytical models to include the perforation effects in squeeze-film damping calculations. However, there is a lack of works in modeling the squeeze-film damping in perforated Torsion Micro-mirror.

This paper presents analytical solutions for the effect of squeeze film damping on a rectangular perforated Torsion Micro-mirrors. We modified the Reynolds equation to extend its applications to squeeze-film air damping of perforated plates by adding a term related to the damping effect of gas flow through holes. The double sine series solution are derived for the linearized Reynolds equation to obtain the pressure distribution under the vibrating plate, and then we calculate the analytical expressions for the spring constant and the damping constant. By comparing the results with the finite element method, the accuracy of the model can be verified.

The lateral impact tester is the key-device to test the naval ship devices' properties of resisting non-contact explosive impact, and used to simulate the shock response of shipboard under naval dual-wave shock. Trial device installed on the top surface, it generates a huge overturning moment on tester and subsequently leans to the one-side of the impact cylinder when the positive wave is shocking the trial device. The vibration of trial device causes the rail of tester to generate periodic positive pressure and friction. To study the effects of output waveform produced when the vibration and friction are impacting on the impact table. This paper analyzed the motion regular of the tester based on finite element method. And there is a discovery: the vibration and overturning moment of trial device itself had no effect on the impact tester displacement almost and slightly effects on velocity of impact table, but has significant effects on the acceleration of the impact table, not only make the acceleration peaks of the positive waves significantly changed, but also the negative waveform appears jaggy. The vibration and overturning moment of trial device greatly increases the friction of the rail, and the friction changed periodically with the changes of vibration of the impact tester. The experimental results of the research have the meaning to guide the design of lateral impact tester.

The transverse impact testing machine is the important equipment for testing naval craft. Against the underwater non-contact explosive impact performance, this used to simulate the hull's response under the positive and negative wave impact. The tested equipment is installed on the impact table. When positive wave impact, the device produce a huge overturning moment to the equipment and at the same time, the device tilt to the impact cylinder side. The rails of impact table produce the periodic positive pressure and friction because of equipment oscillation during the negative wave impact process. To research output waveform of the dovetail guide bounce table, with a finite element method analysis the friction force and motion law of the bounce table. It was found that: the overturning moment acts on the rail make the dovetail guide creates a huge contact force and friction force. The equipment oscillation have a significant effect on output waveform of bounce table, not only the positive wave acceleration peak significantly increasing or decreasing but also make negative wave appear jaggy. Friction force of the dovetail groove reduces the peak speed of the bounce table, make the negative wave process finish in advance and reduce displacement of the bounce table. The researches have a certain significant guidance on the design of transverse impact testing machine.

A rigid-flexible coupling and strongly nonlinear system has complex dynamic behavior. We constructed a planar spring-rod model which consists of two-time-scale variables. A cubic interpolation precise integration method was applied to solve the dimensionless dynamic equations. We employed the Poincaré maps and the maximum Lyapunov exponents to analyze the dynamic behavior of the spring-rod system. Numerical simulations results demonstrate that the system presents a chaotic motion in the condition of different controlled parameters, and the controlled parameters space corresponding to the motion state of the system was given.

In the steel metallurgical industry field, the slab surface temperature which has a close relationship with the quality of the casting is one of the important information of continuous casting. An online Numerical Dynamic Heat Transfer Simulation of Continuous Casting Slab is put forward to guide temperature measurement of the slab in this article. For attaining the heat transfer simulation of high accuracy, a two-dimensional dynamic mathematical heat transfer modeling of continuous casting slab multilayer structure has been presented. The fluctuation of measured temperature has been reduced to under 10°C with thermal imaging measuring result. So it provides the possibility for the online process control. For the validation of the dynamic modeling, a series of slab surface temperature measurement were carried out on the actual casting process. Finally, the dynamic modeling can do help to adjust the operating parameters to improve the casting quality.

The study reports the fundamental mechanism of the significantly enhanced damping property of nitrile butadiene rubber(NBR) following the introduction of hindered amine(GW-622) small molecules. The formation of hydrogen bonds can be observed between NBR polymer chains and GW-622 by means of molecular dynamic(MD) simulation. When NBR is mixed with different GW-622 mass ratios, there is an optimum mass ratio of NBR/GW-622(100/64),in which the NBR/GW-622 composites have the largest H-bonds, highest cohesive energy density(CED) and smallest fractional free volume(FFV), indicating the strongest intermolecular forces and best damping property.

The Fe₃O₄ nanoparticles coated by citrate (citric acid, CA) were prepared by chemical co-precipitation method. Via Stokes polarimeter, the variation of retardance in water-based CA coated Fe₃O₄ ferrofluids (FFs) with different molarities of CA solutions was measured and compared. Next, the verification of the sample with the second high retardance using orthogonal test of L₉(3⁴) in our previous study was executed. Further, the heating performance of this CA coated FF sample with high magnetic retardance and response in the alternating magnetic field was investigated. When the concentrations of CA coated FFs were 2mg/ml and 50mg/ml, under the external alternating magnetic field with applied apparent current of 300A, after heating 76s and 16s, the temperature of the CA coated FFs is greater than 45°C, respectively, reached the requirements for the magnetic inductive heating treatment of medicinal cancer tumor.

Only get passed in approval test and evaluation land-based, could shipborne weapon system (SWS) be loaded on ship for sea test. While in land-based test, how to simulate the effect of sea wave impact to SWS has been an insoluble problem for decades. For now, the frequently-used methods included building of large pool or developing of simulator to simulate sea wave impact. However, the two methods took on the problems of expensive cost, sophisticated test process, long test period, etc. In this paper, a novel easy and feasible method to simulate the influence of sea wave was introduced, which used a sea wave impact simulation test system in approval test of SWSs. On the basis of impacts modelling for multiple levels of sea wave, the ship movement under sea wave impact was superposed to the flying route model with combined use of equivalent substitution theorem, coordinate mapping and signal input simulation methods. Thus, the influence of sea wave impact on SWSs was simulated. Simulation and test results indicated that the simulation test system met the requirements of terrestrial type approval test for SWS.

A new method is proposed to test the flexural rigidity of woven fabric based on image analysis. The major intention is to enhance the accuracy of virtual clothing via the actual bending stiffness of real fabric. A fabric bending device is developed to collect the bending shape of woven fabrics under the cantilever beam test. Due to the fact that the warping of fabric is inevitable, a mid-curve selected from five target curves representing the bending shape of the fabric is proposed for evaluating the bending performance of woven fabric. The calculations and test methods are validated by experimental observations. The results are further correlated with that of KES-FB2 test. It has been proved that the mid-curve can be employed as an efficient approximation in computing the flexural rigidity of woven fabric.

The study firstly addressed the dynamics of droplets during passive micromixing program using obstacles and porous media by modified lattice Boltzmann method (LBM). The modified Shan-Chen model was introduced in LBM. The simulation results show that, the inlet velocity plays a more important role in the coalescence length than the size of obstacle when droplet passing a cylinder at the microscale. There exists a critical obstacle size, beyond which the big obstacle is unfavorable to generating small droplets. The metal foam is more beneficial to generating smaller droplets than obstacle at the microscale. Big PPI is favorable to the formation of small droplets. The simulation results indicate the great potential of metal foam in generating smaller droplets because its porous stricture effectively reduce the second coalescence of broken droplets.

In the process of injection molding will produce residual stress. It can seriously affect the product's shape, surface quality and usability. In this paper, on the basis of the source of the residual stress produced, by using MOLDFLOW software, with the aid of orthogonal optimization method, optimize the injection molding process parameters, to determine the combination of optimal parameters, and significant influence on residual stress were obtained through the analysis of variance of parameters. So as to achieve the aim of improving product quality, this has a certain meaning for actual production application.

To study nonlinear dynamic characteristics of the gyroscope rotor system, a dynamic equation of rolling bearing rotor system considered multiple nonlinear factors such as varying compliance and nonlinear bearing force is presented. Using Runge-Kutta method, it is solved for different parameters. The bifurcation diagrams, the Poincaré maps and the frequency spectrums are given. Study results show that rich periodic, non-periodic (quasi-periodic and chaotic) vibrations and period doubling bifurcation exist in this system with the change of working parameters. Instability of the system can be reduced by selecting reasonable parameters. These results are further verified by the maximum Lyapunov exponents.

Lattice Boltzmann method (LBM) combining with LES is developed in the paper to simulate fluid flow at high Reynolds numbers. A subgrid model is used as an LES model in the numerical simulation for high Reynolds flow. The idea of subgrid model is based on an assumption to include the physical effects that the unresolved motion has on the resolved fluid motion. It takes a simple form of eddy-viscosity models for the Reynolds stress. Lift and drag evaluation in the lattice Boltzmann equation takes momentumexchange method for curved body surface. First of all, the present numerical method is validated at low Reynolds numbers. Second, the developed LBM/LES method is performed to solve flow problems at high Reynolds numbers. Some detailed quantitative comparisons are implemented to show the effectiveness of the present method. It is demonstrated that LBM combining with LES model can efficiently simulate high Reynolds numbers flows.

According to the reinforcement on pre-stressed anchor cable frame of a slope design, based on the field test to study the stress distribution and stress-strain characteristics of pre-stressed anchor cable frame system in the slope reinforcement. Through the testing of internal force of frame structure to acquire the internal force distribution of framework in different loads and the maximum bending moment position of beam and vertical rib of frame, the results showed that the maximum tensile bending moment are located around the anchor hole and the minimum bending moment which is in a state of compression in the middle of a beam (or vertical rib); also the safety of Winkler elastic beam theory to calculate bending moment is verified. Carried on the strain test for the anchoring sections of a pre-stressed anchor cable under concentrated tension (PACCT) and a pre-stressed anchor cable under dispersive pressure (PACDP) to acquire the strain distribution of anchoring sections when the different types of anchor cable is working, calculated the maximum shear stress positions of different types of anchor cable's anchoring sections, the calculating results show that the peak value of PACCT's shear stress is located at the bottom of the grout and the peak value of PACDP's shear stress is located near the anchoring steel bearing.

The shear strength of unsaturated soil is one of the important engineering properties. On the basis of referring to the Chinese and foreign literatures, mainly from the theories and formulas, instruments as well as the specific aspects of the experimental research results to summarize, the paper outlines the advance in research on shear strength of unsaturated soil. Although different scholars have carried out extensive studies and obtained certain research results, also, the view of the difference between shear strength of unsaturated soil and shear strength of saturated soil is the matrix suction's contribution to the strength is approved by academia now. There are still some problems that the scope of shear strength formulas of unsaturated soil, the difficulty of measuring matrix suction and the experimental conditions can't reflect the real stress state of unsaturated soil. Therefore, the further researches are needed to improve the shear strength theory system of unsaturated soil.

Crack Tip Fields, base on Reissner plate theory, the interface fracture of homogeneous material spherical shells bonded to linear functionally graded materials (FGMs) ones is studied. The higher order crack tip fields of homogeneous materials and FGMs regions are obtained by the eigen-expansion method, respectively. The relations between undetermined coefficients can be obtained by continuous conditions of stress. Finally, the structure of higher order crack tip fields is analyzed.

Research on the buckling of isotropic nonlinear viscoelastic plates is introduced. The material is assumed to be nonlinear viscoelastic and obey the Leaderman nonlinear constitutive relation. The static governing equation of nonlinear viscoelastic plates are the combination of the equilibrium equation and the deformation compatibility equation, which is simplified into a nonlinear integro-differential equation. Through the numerical results we derived the different buckling deformation while the pressure parameter f is change, and the different buckling deformation while viscosity coefficient η vary.

In order to study the mechanical performance of the double-layer high-strength spiral stirrup confined concrete circular column under axial compression load, based on the domestic and foreign scholars on the study of confined concrete, according to the test results, the finite element model of the double-layer high-strength spiral stirrup confined concrete circular column is simulated. Then the mechanical property of the high-strength spiral stirrup and concrete are analyzed. The results indicate that the simulation results are in good agreement with the test results. The double-layer high-strength spiral stirrup can restrain effectively horizontal deformation of reinforced concrete. The effective constraint has significant effect to improve the ultimate bearing capacity and ductility of reinforced concrete columns, and the results are inclined to safety. Therefore, the model can be used in nonlinear finite element analysis of the double-layer high-strength spiral stirrup confined concrete circular column.

The finite element analysis has been widely used in analysis of tubing string and down-hole tools characteristics. Low cost, short circle and visualization make finite element analysis possess more advantage. The paper introduces the application of finite element analysis in mechanics analysis of completion packer by establishing the finite element models, meshing and the analysis results of slips and rubber of THT completion packer. Based on the analysis, it can be got that the finite element analysis can simulate the contact analysis of slip teeth and rubber well; and the distribution of contact stress between slips and casing is uneven both in axial and circumferential; the rubber can seal effectively between the tubing string and casing, the contact stress of rubber-casing indicates that the stress distributes in linear along the axial. The stress near the loads is larger than others due to the friction between rubbers and casing.

In order overcome the defect of passive control of oleo-pneumatic shock absorbers, a new structure of magnetorheological shock absorber is proposed. Its damper characteristics are test by vibration test bench, and its damper model is built by the method nonlinear hysteretic biviscous damper model. The parameters of damper model are identified by least square method. The damper model can effectively characterize the intrinsic nonlinear behavior of shock absorber. Compared with the results of experiment, the maximum of relative error of damper is less than 13%.

The paper presents massively parallel simulation of the flow characteristics in a submersible axial flow pump using OpenFoam code. The calculation is done on a SUGON high-performance computers using 160 CPU core. The finite volume method is used to solve the governing equations and the pressure-velocity coupling is handled via a Pressure Implicit with Splitting of Operators (PISO) procedure. Simulation results have shown that the pressure and the velocity of flow distribution in the impeller region is relatively higher than other regions.

The paper presents numerical study of unsteady cavitating turbulent flow in a tubular turbine runner. Analysis was performed by OpenFOAM code. A mixture assumption and a finite rate mass transfer model were introduced. The finite volume method is used to solve the governing equations of the mixture model and the pressure-velocity coupling is handled via a Pressure Implicit with Splitting of Operators (PISO) procedure. Simulation results show that the volume fraction of water vapor on the upper of runner is relatively high and the volume fraction of water vapor on the suction side of runner is higher than which on the pressure side. It will lead to cavitation or fatigue damage.

The paper comparative researched the dry air, nitrogen and helium and other effects of three kinds of commonly used sensitive gases on the sensitivity of the piezoelectric fluidic angular rate sensor. By using the finite element method, calculated the flow field in sensing element of piezoelectric fluidic angular rate sensor under the effect of the input angular velocity of 20°/S The results are as follow: (1) Changing the type of sensitive working gas in the piezoelectric fluidic angular rate sensor sensitive element, the distribution of flow field also changes. (2) The input angular velocity is 20°/S, the airflow velocity difference between two heat resistance wire r1 and r2 namely ΔVN2> ΔVAIR> ΔVH. (3) The sensitivity coefficient, namely KN2> KAIR> KHe, among them, KN2 is 1.05 times of KAIR, KHe, is 0.21% of KAIR. (4) Nitrogen is corresponding to the highest sensitivity, the thermal resistance wires antioxidant, stability is better, but the cost is high; sensitivity of dry air secondly, the thermal resistance wires easily oxidized, poor stability; helium corresponding to the minimum sensitivity, thermal resistance wire is not easy to be oxidized, the best stability. This paper explained the mechanism of sensitive working gas influence on sensitivity of piezoelectric fluidic angular rate sensor, in order to improve the practicability of the piezoelectric fluidic angular rate sensor, meet different engineering needs to open up a new way.

The software compensation technology of the piezoelectric fluidic gyroscope based on DSP digital processing is designed in the paper. Using the DSP, the zero-temperature compensation, sensitivity-temperature compensation and nonlinearity compensation could be solved by combining method with the data interpolation and the second table look-up. The experiment results are as follow: after the software compensation, the zero-temperature drift declines from ≤1.5mV/°C to ≤0.2 mV/°C, the sensitivity coefficient declines from ≤2mV/°/s/°C to ≤0.2mV/°/s/°C, the nonlinearity declines from ≤5% to ≤1.2%, in the measurement range of −60°/s~+60°/s, working temperature range is extended to −40°C~+60°C. such compensation technology, simple. It has practical value to improve the performance of fluidic Gyroscope temperature and linearity, expand the field of the use of fluidic Gyroscope.

Predicting thermoelastic damping (TED) is crucial in the design of high Q microresonators. The fully clamped rectangular plates are common elements in some microresonators. In this paper, an underlying theoretical framework is developed to calculate the TED in fully clamped rectangular microplate. Using this framework, an analytical expression for TED in the fully clamped rectangular microplate is presented. The three-dimensional heat conduction in the microplate is considered. The 3-D temperature field is approximated by the sine series. The present model is validated by comparison with the previous model and the finite element method (FEM) model.

The screwed fastening is one of the weakness of ship shock resistance performance. As shown in the statistics, there are 40% of the damaged cases having relationships with screwed fastenings in the shock tests of the shipboard equipments. One problem is the implementation of impact to the screwed fastenings in the event of encountering a shock loads. By means of the split Hopkinson pressure bar and tie bar experiments, using the Johnson-Cook model to matching the experimental results, get the yield strength under different strain rates of the three kinds of screwed fastenings materials. By comparing with the yield strength getting from quasi-static experiment, the yield strength obtaining from shock tests has improved 1.3 times at least. Consequently, shock loads can improve the yield strength of screwed fastenings within certain limits and it is safe to choose the screwed fastenings basing on the machinery handbooks.

Pull-in instability of a cantilever nano-actuator was analyzed considering the fringing field and the Casimir force. The instability parameters of the actuator were determined analytically under the assumption of a second-degree shape function for the beam. The influence of the Casimir force and the fringing field effects on the pull-in parameters was investigated. The results demonstrate that the Casimir force decreases the pull-in deflection and voltage, the fringing field effects decrease the pull-in voltage, but the influence on the pull-in deflection depends on the Casimir force parameter.

The metering device is an important part of no tillage planter, planter plate suction performance directly affects the work quality of no tillage planter of the whole, seed dispersion degree have important effects on the seed plate seed suction performance, and the vibration is an important factor affecting the seed of discrete degree.

This paper applies a discrete element simulation software to monitor the indoor corn seed population movement, get the speed of planter plate is 21.7r/min, the seeding indoor filling 4500 grain, seed metering device when the amplitude is 2.11mm, the vibration frequency were 10Hz, 20 Hz, 30 Hz, 40 Hz, 50 Hz, 60 Hz, 70 Hz of the seeding influence indoor population movement. By the discrete element software processing module, in the 2S time average velocity of maize seed; we take 0.01s as the maximum average velocity interval all time points and minimum average speed. We perform the fitting curve of vibration frequency and the mean velocity of corn seeds with origin software. Simulation results show that the seeder vibration frequency is 10Hz, the smaller population movement; from 20Hz to 70Hz, the vibration of the larger population; seed metering device of vibration frequency of about 30Hz, the largest population movement. Provide the basis for the indoor discharge experiment.

The steady-state response of linear fractional vibration system with harmonic excitation was considered by using the fractional derivative where the time interval is (−∞, t). We adopted the harmonic excitation in the form of complex exponential function, and used the method of undetermined functions to obtain the steady-state response with the same frequency as the excitation. The amplitude-frequency relation and phase-frequency relation were derived explicitly. The results show that the order and the coefficient in the fractional derivative term influence the stiffness and damping of the system, the amplitude-frequency relation and the phase-frequency relation.

To improve the effectiveness of concrete faced rock-fill dam monitoring model effectively during initial impound period period, after the analysis of the characteristics and application of various models, we proposed the improved relevance vector machine model for crest settlement of concrete faced rock-fill dam during initial impound period period. According to the characteristic of the crest settlement of concrete faced rock-fill dam during initial impound period, we used a composite objective function to solve the problem of over-fitting. Case study demonstrates the model has high generalization ability.

To investigate the dynamic performance of spring-loaded pressure relief valve (PRV) under high temperature and high pressure steam (HTHPS) conditions, experiments according to ASME PTC 25 and a new transient numerical simulation method were carried out. The validity of accuracy of the simulation was confirmed by comparing the results of simulation and experiments. It was found that the usage of a vessel (connected to the outlet of PRV) whose diameter is one order higher than the PRV orifice diameter is necessary in the simulation of HTHPS PRV. During the PRV experiments, friction existed between moving disc and fixed components, which could alleviated the fluttering. The experiments and simulation on performance of HPHT steam PRV should be strictly carried out using HPHT steam not air to avoid inacceptable uncertainties.

Three-dimensional modeling software and dynamics simulation software were used for fatigue design of the connecting rod. Dynamics simulation model of crankshaft system was established and the load of connecting rod was obtained. Non-linear contact analytical method of static strength was adopted to accomplish the stress distribution of the connecting rod. On the basis of the static strength analysis, fatigue life and fatigue safety factor of the connecting rod were get by fatigue strength analysis. Compared with experiment and engineering calculations, co-simulation method of multi-software is more economic and accurate. Furthermore, optimal design of the connecting rod would be benefit from the calculation results.

With the help of Stokes number of particle, the erosion behavior of wind turbine blade was studied by analysing the process of sand impact with its airfoil. It is found that the sands will bypass the blade and no erosion formed when the Stokes number of particle is smaller than a certain value. With the increase of the Stokes number of particle, the sands begin to impact the blade and erode it, and the erosion area will expand gradually from blade leading edge to entire pressure surface. The most serious erosion must be located at the two sides of the stagnation point.

T branch tunnels are a kind of common underground space. It is very important to study the propagation characteristics of gasoline-air explosions in T branch tunnels, which will not only enrich the theories of gas explosion in confined space, but also lay the theoretical groundwork for disaster alleviation. Based on explosion experiments and numerical simulations, this paper analyzes explosion overpressure, flame velocity and turbulence intensity of gasoline-air explosions in T branch tunnels. Furthermore, a visualization research is conducted on how the flame passes through the branch tunnel. The main contributions of this paper are as follows. 1) It points out that the two major disturbance sources and the changing section-crossing are the main factors affecting explosion propagation; 2) The disturbance sources will lead to turbulence, which will cause explosion overpressure and increase flame velocity considerably; 3) As the flame passes through the branch tunnel, the detonation wave will go through four processes, namely detonation wave deduction, partial flame extinguishment, flame re-ignition and gradual increase. 4) The explosion in confined space could cause gas backflow, multiple explosions, pressure oscillation and multiple pressure peaks.

An aerodynamic optimization design study of a transonic compressor blade is carried out based on the three-dimensional parametric approach of local shape function. To avoid too many design variables and repeated mesh generation of optimized blade compare to the traditional approach in blade optimization. Mesh deformation technique of the reduced control points based on radial basis functions (RBF) is proposed, which combined with gradient based optimization algorithm, to solve the blade optimized problem. Analysis showed that: RBF mesh deformation technology could largely shorten the time of mesh generation without reducing the quality of meshes; the computational time was reduced greatly due to the gradient based optimization algorithm; the optimized blade increases the total pressure ratio by 0.86%, the adiabatic efficiency by 1.79% and the mass flow by 0.6% under the condition of consistent certain pressure outlet. The improvement of blade performance mainly is owing to the decrease of passage shock intensity.

This paper makes a simulation analysis on three kinds of micro droplets jetting dispenser nozzle match type (the cone-cone match, sphere-cone match, sphere-sphere match). The key parameters of coordination including the average working pressure P, nozzle colloid flow time t0 the jet nozzle colloid duration are analyzed in order to acquire the properties of various match type. Conclusions was drawn based on the comparison between the different match type that sphere-sphere coordination is better able to dispense large viscosity colloid and reduce the angle in low viscosity; cone-cone coordination is not suitable for dispensing due to low speed of liquid ejection; spherecone coordination is suitable for dispensing colloid of lower viscosity. These findings are of great significance for the development of on-off valve jet dispensers.

The research purpose is to deal with low efficiency of hydraulic transmission system. Vehicle powertrain system was built by applying SimDriveline module. The fundamental schedule of efficiency shift was introduced. A double-parameter fuzzy controller was designed to realize automatic shift. Finally, the simulation model of double-parameter efficiency shift was established in order to verify the correctness of efficiency shift based on fuzzy control. The simulation results indicate that, according to the changing of load, the vehicle can complete automatic shift whether in starting condition, operating condition or climbing condition. The hydraulic torque converter can constantly work in high efficient area, which demonstrates the feasibility of the designed fuzzy controller.

Studying the characteristics of gear meshing is significant for improving the transmission performance of a gearbox. According to the structure of the off-road vehicle gearbox, the dynamics virtual prototype model of the gearbox transmission system was established by ADAMS. Based on Hertz contact theory, the dynamics simulation of gear meshing force was conducted with consideration of the influence of manufacturing and assembly errors. The results indicate that controlling the manufacturing and assembly errors can effectively reduce gear noise and gear wear, which improves the working performance of the gearbox.

The purpose of this article is to obtain the transient distribution of flow and valve core stress of the hydraulic poppet valve during opening process. Based the dynamic mesh technology and fluid-solid theory, a numerical model was established using the CFD software. Through comparing the steady displacement simulation results with theoretical values, motion situations of flow, it is shown that the stress of a fixed area changes during the opening process of the valve plug, and the pressure gradient is very large in the valve port. There is a “negative pressure” area in the flow field and the size keeps changing with time, which may cause cavitations. Furthermore, the stress distributions are different even though the displacements of the valve plug are the same due to different velocities at different time. These results provide the basis for the design and optimization of hydraulic poppet valves.

In In order to obtain the transient characteristics of hydraulic poppet valve during opening process, a hydraulic poppet valve dynamic numerical model was proposed based on the CFD and dynamic mesh technique. It is shown that the steady state flow and transient flow fluctuations both decrease along with the increase of the spring stiffness. Furthermore, as the total force on the hydraulic poppet valve plug increase to step up the spring stiffness, the steady state displacement of the valve plug decreases and the valve plug arrives at the equilibrium position faster, which is good for reducing impact and vibration.

This paper focuses on analysis of power transmission system, the power life of engineering tractor, which plays a very important role in the face of complex working environment and poor working conditions. The establishment of tractor power-train model, supported by AVL-Cruise, is the simulation and calculation foundation of the tractor power and fuel economy performance. The calculation results of the simulation task are compared with the original car data. That shows the improvement of tractor performance. The optimization is based on the simulation results. It increases the power performance for 4.23% and decreases the fuel consumption for 4.02% at cycle conditions.

Transient simulation of heat properties for vehicle exhaust system components plays an important role in vehicle development process. Simulation analysis can find thermal materials risk in early stage of project, and quickly give proposal so as to reduce test cost. Based on STAR-CD software, a vehicle exhaust system model, which includes the exhaust gas, the exhaust pipes and aftertreatment devices, was established. A three-dimensional transient simulation was undertaken for the heat properties of vehicle exhaust system components. The heat properties with the periodic pulsating exhaust gas velocity were obtained and analyzed, and the transient mean value were compared with the steady results, the results show the predicted the unsteady mean exhaust gas surface temperatures are higher than 50°C,the unsteady mean surface heat dissipating capacities of exhaust gas system components are 11.3 percent up at the 10% pulsating exhaust gas velocity condition.

The interaction influence between engine and the vehicle model is mainly manifested in two aspects: drive torque fluctuate which exerts on the flywheel, the engine block motion and chassis structure motion interaction. Review of the current model of engine in the literature briefly, the high accuracy model is unable to realize the real-time simulation; the existing real time model is steady-state model, which can't depict the fluctuations of driving torque and the motion interaction between engine and chassis. The quasiinstantaneous engine model based on indicator diagram is built, which requires only some basic characteristic parameters, no geometrical parameters, so that greatly reducing the modeling effort. At the same time, through the establishment of the six degrees freedom engine block model, the engine block motion and chassis structure motion interaction is described. The simulation results of engine integrated in vehicle show that the quasiinstantaneous engine model achieves good performance, compared with steady-state engine model, and achieve real-time simulation.

Torsion fatigue tests with solid cylindrical bar specimens have been carried out to investigate the effect of mean shear stress on the torsion fatigue failure of 30CrMnSiA steel. The relationship between mean shear stress and fatigue life under two different values of shear stress amplitudes was obtained. Tests results showed that fatigue life does not change significantly with increasing the mean shear stress, which indicates mean shear stress has little effect on fatigue life under torsion loading. Fracture appearance is almost perpendicular or parallel to the specimen axis under different mean shear stresses, and the torsion fatigue failure is dominated by shear stress amplitude.

In this paper, the displacement and stress fields of the surrounding rock of tunnel in soft rock are analyzed by using FEM software ANSYS. And the impact of bolt pre-reinforcing measure on deformation of tunnel surrounding rock has been considered. The result shows that the displacement and stress fields of surrounding rock have no obvious change when taking reinforcing measure. But these measures, at some level, can play a positive role in reducing the settlement of the vault and the stress relaxation in surrounding rock and controlling the deformation of surrounding rock.

Selection of excavation method plays an important role in the safety and efficiency of tunnel construction. Due to the special geological conditions under the bias tunnel with soft rock and larger span, the excavation method is more critical to prove the safety of tunnel construction. In this paper, based on the object of bias tunnel with soft rock and larger span, the effect of coil soil on stability of surrounding rock is analyzed, which provides a reference for further safety construction.

The forced mechanism of end milling cutter was further analyzed theoretically when cutting. A force model on micro milling was established. The micro milling experiments were carried out using micro milling cutter. The data of the milling force acting on micro cutter blade was collected and analyzed. The diagram of micro milling force and cutting parameters was intuitively built. The laws on the milling force change were derived from the diagram. The effect of the cutting speed, feed rate and cutting depth on the milling force was got. The results provides the theory basis for t the controlling of machining accuracy in micro-milling.

Based on the basic design theory of centrifugal pumps, the impact losses of impeller are studied by using velocity triangle. Phenomena of the impact losses near the inlet of the impeller under off-design condition are described systematically. The effects of inlet impact angle with the flow rates on the impact losses is analyzed and calculated. The trends of losses under design and off-design modes are found. The model provides a practical method for optimization design and operating condition of centrifugal pumps.

Current models for joint interface contact of rough surfaces are typically based on the statistical and fractal methods. In this paper, a machined surface topography is measured using 3D confocal microscopy. Surface data is preprocessed using wavelet algorithm and the least square method and a digital surface with roughness information is obtained. Then, real joint interface contact is calculated using Fortran language. Load, deformation, stiffness and other parameters during the contact process are also calculated. Comparison of the experimental and calculated values, show that the joint interfaces obtained from the digital surface with the roughness information can be used to replace the original real surface accurately. Results are valid and normal contact stiffness increases with the contact pressure exponentially.

The fire damper is a very important equipment for stopping the fire and smoke through from fire sites to other safety areas. Since the fire dampers are the necessary equipments in the building law, all the performance requirements and procedure documents are need to be prepared and studied. The performance of fire damper in HVAC duct are investigated in this paper by computer simulations. Different smoke leakage conditions are studied in HVAC duct to evaluate the smoke layer, temperature and CO₂ levels in fire zone and next zone.

Traditional maintenance and support technologies cannot meet the requirement of the safety, reliability and economy of nuclear power plants. The prognostics and health management (PHM) technology is a technology of on-condition maintenance, and it is significant meaningful to preserve the safety and reliability of nuclear power plants. In this paper, the conception and significance of the PHM technology are introduced. The key technologies of the PHM system are stated. The feasibility of the PHM technology in the pressurized water reactor nuclear power plant (PWRNPP) field is analyzed. The centralized-distributed PHM system of PWRNPP is designed.

To ensure the crane stiffness and strength to meet the design requirements of this project, with the current virtual prototype matures finite element software technology, the use of Pro / E software to generate a steel frame structure model, imported into ANSYS software, finite element stress analysis of steel frame case to determine whether static steel meets the requirements, and then use the I-DEAS [1] software to optimize the design of steel structures, steel structures designed to make more rationalized based on the analysis results.

A biasing shape memory alloy (SMA) rigid elastic coupling drive sucker control system has been designed. Using field programmable gate array (FPGA) for generating a pulse width modulated control mode, build a resistance detection feedback circuit feedback control to the current, and the measurement of the negative pressure sucker sucker, realize the bionic micro SMA drive control. Through the thermal dynamic analysis of the component process of state changes in suctions flow field was described, and the principles of the adsorption system were revealed. The results show that negative pressure can be stably generated and the system realize firmly adsorbing on wall. The theoretical and experimental result of wall climbing robot contributes to further perfecting the performance of robot.

Focused on the differences between theoretical design and the torsional broken conditions in practical of the shearer drum's torque axis, this paper begins with simulating the field situations to paint the torque and the curve of torsion angle when the torque has been broken down. Analysis of the hardness of the fracture, microstructure, chemical composition and the finite element simulation of test procedure can determine specimen materialand calculate the difference between the actual and theoretical calculations breaking torque and finite element simulation values. The results show that, based on the differences by comparing material processing technology to determine the shear strength τ_b, different ratio coefficient k on the result of theoretical design and calculation, it is obtained correction method of the design formula by the analysis theory for modifying parameter and improving the reliability of the shaft torque.

Results from experimental investigation and theoretical analysis of the relative velocity field inside a model centrifugal impeller were described and discussed. The experiments were performed in a specially designed perspex impeller of four logarithmic blades by employing a two dimensional particle image velocimeter system. Streamwise velocities were measured at three rotating speeds and three flow rates for each speed. Based on the experimental data, some important flow rules were formulated, theoretic explanation by means of vector analysis and potential flow theorem were also offered in the paper, which will contribute to improving pump performance.

Flow separation from blade surfaces caused by high adverse pressure gradient within low specific speed impellers contributes considerably to the low efficiency of the impeller. Authors of this paper showed two important geometrical involute properties of involutes by kinematics theorems, which are expected to control flow separation and improve hydraulic efficiency of impellors. CFD results indicate that involutes are superior to other curves commonly used in hydraulic features. Detailed calculating and drawing process about the involute is presented in the paper to help engineers apply this new type of curve in cylindrical blade design practice.

Based on finite element software the paper established three dimensional finite element model of premium connection taking screw-liter angle into consideration, simulated the process of making-up exerted by the optimal torque and analyzed the seal characteristic of premium connection exerted by bending load. The results showed that three dimensional finite element method can completely simulate the process of making-up, and the stress changes are consistent with the actual situation. The annular contact stress of primary seal and shoulder exerted by the optimal torque are large enough and normal. The contact stress of the seal will decrease exerted by bending load, but the annular contact stress of seal under bending load is large enough to ensure the seal ability, the contact stress of stretched side shoulder is zero due to a space. Bending loads have a greater impact on the stress distribution of thread, which lead to increasing possibility of thread galling, reducing the strength of the threaded connection.

With the advances in technology underpinning the design of armaments, unmanned combat platform has been developing rapidly in recent years. Using Finite Element Analysis (FEA) module of the SolidWorks software, Static and Model analysis could be performed by setting thickness of parts as variables, to study the stress distribution and natural frequencies, so as to obtain the optimal design, in terms of reliable performance for frame structural and lightweight frame.

In this paper a novel rapidly dynamic Var compensator based on voltage source converter (VSC) is proposed. Sinusoidal pulse width modulation (SPWM) controlled voltage source converter (VSC) is employed in this compensator in order to regulate the compensation reactor voltage and output continuous inductive reactive power. With this compensator, the harmonics issue of thyristor controlled reactor (TCR) is overcome and the capacity of the inverter is only 25% of the rated capacity. And a reactive power compensation equipment is proposed comprising the novel compensator and a series of thyristor switched capacitor (TSC). By adopting the proposed design, the capacity of dynamic Var compensation could be reduced greatly as well as realizing the bi-directionally continuous compensation of reactive power.

Under the condition of monopole-ground operation, there will generate neutral current in HVDC transmission system. Therefore DC magnetic bias happends on transformers and results to transformers overheating, vibration, noise and so on. In this paper, we discussed the influence of DC magnetic bias on transformers and proposed a suppression method based on DC electric potential compensation. In addtion, we presented a novel topology of a device based on the method above. What is more, we ran the Simulation models with PSCAD/ EMTDC and the results prove that the method has a satisfying performance on restraining the neutral current.

The modern large-scale electric arc furnace have a large capacity. The fast-changing load will cause serious voltage fluctuations in grid. Moreover, due to the random variation of the arc length, the power will fluctuate greatly, which also has a bad effect. This paper analyzes the principle of voltage flicker suppression and power stabilization based on SPLC, proposes a multi-target control strategy of SPLC to suppressing voltage fluctuation and power fluctuation caused by electric arc furnace simultaneously. Simulation results show that the proposed method can achieve the multi-objective control target of SPLC, helping improve the production of electric arc furnace, and reduce the adverse effects of electric arc furnace on the grid.

This study employed different heat dissipation configurations of LED streetlight modules to investigate the changes in luminous flux, correlated color temperature, and temperature of the modules. Heat-dissipation plate-fin and polymerizable liquid matrix thermal conductive material (thermal grease) were used to devise four types of LED streetlight modules. Subsequently, light decay ratio, color shift, and temperature distribution of LED modules were compared and comprehensively analyzed to determine the changes in the efficiency of heat dissipation in the modules. The streetlight modules produced were switched on for long periods, and the results indicated that the module comprising both the plate-fin and thermal grease outperformed the other modules. Combining heat-dissipation plate-fin with thermal grease (a thermal conductor) yielded a product that exhibited a light decay ratio of 87.6% and color shift of approximately 2.5%. An infrared thermometer was then used to measure the temperature at the center point of the modules, showing that the temperatures of the LED modules were exceedingly lower than those of other modules. The results verified that an effective heat dissipation configuration lowered the temperature of LED modules, thereby enhancing the luminous flux and preventing color shift. To verify the validity of the experimental results, we compared the results with those of previous studies [1]–[6]. In addition, the plate-fins were modified in terms of spacing, height, length, thickness, and surface coating to optimize the effects of heat dissipation. This study adopted heat-dissipation plate-fin combined with thermal grease as a thermal conductor and various measurement methods (such as an integrating sphere instrument to measure and verify the light decay ratio and color shift, thermocouples, and infrared thermometer) to verify whether the temperature at various points on the lighting module differed when various heat dissipation configuration was used in the lighting modules. Overall, the experimental results indicated that a superior heat dissipation configuration lowered the overall temperature of LED modules, thereby enhancing the luminous flux and preventing color shift.

A computational study of the bandgap structure in two-dimensional (2D) photonic crystals (PhCs) with both square lattice and triangular lattice has been investigated in this paper. By studying in-plane light propagation in 2D PhCs, we solve the partial differential equations (PDEs) with periodic boundary conditions by using the finite element method (FEM) in frequency domain. The numerical results show that the numerical method is efficient and convergent. Moreover, based on the finite element procedure, a new numerical design scheme has been presented to obtain a desired photonic bandgap structure, which demonstrated by a design experiment in triangular lattice.

Compared with the traditional catheter type gastrointestinal endoscopy, the wireless capsule endoscopy can alleviate the pains of patients to the minimum. However, every gastrointestinal check takes too much time of doctors, and in some area of digestive tract there exist missed diagnosis sometimes because of the uncontrolled moving of capsule endoscopy. In this paper, a system composed of three sets of orthogonal coils is established. By controlling the current intensity and direction of the coils, a resultant magnetic field can be obtained. This magnetic field will act on the internal capsule endoscopy whose outside is covered with a kind of permanent magnet material, and make it move forward or backward, twirl with multi-angle. The wireless capsule endoscopy driven by external magnetic field will not only improve the success rate of the examination of gastrointestinal diseases, but also reduce the check time of doctors.

In order to design the piezostack precision jetting dispenser applied to microelectronic packaging, ANSYS was introduced to analyze the characteristics of piezostack actuator and displacement amplifier. Firstly, the performance of the piezostack actuator when voltage increased from 0V to 200V was researched. The displacement amplifier parametric model was established and the structural parameters which define its displacement outputting were also discussed. The research indicates that triangular piece length “L0” and actuators spacing “W0” are the major parameters, the displacement changed greatly with them; but preload “F0” and diameter of bolt “D” are the minor parameters. Based upon above rules, the outputting displacement of displacement amplifier is 317μm by ANSYS simulate analysis. And then, the dynamic performance of the displacement amplifier which produced based on optimization design was tested by laser displacement sensor. The experimental results was very close to transient dynamic simulation, and error just 1.1%, which shown the validity of the simulation model. Furthermore, the experiment indicated that maximum output displacement kept the same when working frequency is between 0Hz and 65Hz, but it will drop down as frequency increase gradually. At the same time, to get the maximal displacement outputting, the controlled interval of signal duty cycle would decrease as working frequency increase.

A lumped parameter model is developed to study thermal management system performance of underwater vehicle equipping large power stirling engine. Stirling engine performance and heat release characteristic are represented by models which take effect of cooling water temperature into considered. Stirling engine performance models are validated against experimental data. Cooperated with experimental based models of water pump and heat exchanger, thermal management system performance is analyzed while stirling engine fresh cooling water outlet temperature is set to be at a certain value. The results show that inlet seawater temperature variation has little effect on opening of regulating valve, but engine power output variation results in notably regulating valve opening fluctuation. Modelling results would be employed in a underwater vehicle 300kW stirling engine system design.

In order to study the dynamic characteristic of vehicle-mounted nine-pipe ejector, avoid resonance in weapons firing and vehicles traveling, ensure the shooting accuracy of weapons, this paper establish 3D digital model of the ejector by means of CAD software Pro/E, and establish finite element model by finite element software ANSYS, as well as extract the modal by means of Lanczos. Consequently, the first 6 inherent frequency and vibration modes of the ejector obtained, which provided basis for design optimization, at the same time provide a method as reference in dynamics analysis of other non-lethal weapons.

A traditional pulse generation circuit based on the pulse-forming-line (PFL) is implemented in a commercial 0.13 μm digital CMOS technology. A meandered on-chip coplanar waveguide is used as the PFL and CMOS transistor is used as switch in the Cadence Spectre simulation. The generated pulse duration is determined by the CPW length and the amplitude is close to half the input DC voltage. The results show that the traditional PFL based circuit can be implemented in standard CMOS technology for onchip short pulse generation. Furthermore, the PFL circuits significantly extend the short pulse generation capabilities of CMOS technology.

As LTE use the technology of OFDM, each carrier orthogonal, thus the interference within the district can basically eliminate. But using the same frequency among adjacent cells will produce the large interference, influence reuse efficiency of system, reducing throughput performance of system. Due to this, put forward a adaptive soft frequency reuse resource allocation algorithm based on genetic algorithm. Experiments show that, this algorithm can improve the frequency utilization efficiency and decrease the frequency of the interference between the neighboring cells, optimize the system throughput, improve the quality of service.

In power system, the data synchronization of electronic transformer is the precondition and guarantee for protection's correct operation. In this paper, the origin of electronic transformer data asynchronization is introduced first, and the common interpolation methods to solve the problem are given. Considering the most general form of the sampled signal, the interpolation error expressions of linear, quadratic and cubic spline interpolation methods are deduced and the influencing factors are discussed. Besides, the changing relationships between interpolation errors of the three methods and the influencing factors are calculated by simulation, and the interpolation accuracy of the three methods are compared and analyzed. The research results provide theoretical references for selection of interpolation methods to achieve electronic transformer data synchronization.

In order to find out the relationship between the bonding current and the bonding strength, four sets of experiments, each contains 200 samples, were done with the bonding current limited to 0.05mA, 0.25mA, 0.45mA and 0.65mA respectively. The qualified rate, mean value and standard deviation of the bonding strength measured subsequently were chosen to judge the influence of the bonding current on the bonding strength. The results show that the bonding strength under lower limiting current is determined by the interfacial region, while under higher limiting current, the bonding strength is determined by the glass. With the increase of the limiting current, the qualified rate and mean value of the bonding strength increase first and then decrease, while the standard deviation of the bonding strength first decreases and then increases. Limiting the bonding current is beneficial to improve the qualified rate and stabilize the bonding strength.

The short circuit test belongs to the destructive test and short circuit current is one of the key parameters. The measurement precision of short circuit current directly affects the short circuit test results, so it needs for the evaluation of measurement uncertainty. In this paper, the short circuit current was research object and the research content included six aspects such as the sources of the uncertainty, the establishment of measurement model, standard uncertainty evaluation, combined standard uncertainty calculation, calculated the expanded uncertainty and measurement uncertainty result report. The research was applied in electrical apparatus test.

The current density is a key parameter for thermal stability analysis on short-time withstand current test. It was derived that the relationship for three different current density calculation equations and got the corresponding theoretical analysis conclusion. In case of copper conductor, the actual test verified the correctness of the above theoretical analysis conclusion as the electrical power engineering and electrical product on short-time withstand current test thermal stability design basis. Put forward the design steps to short-time withstand current test for electrical power engineering design and electrical product design to improve its performance.

A model for kinematic analysis of the high speed angular contact ball bearing are constructed. The friction moment model of ball bearing are given. Heat generation of the high speed ball bearing is studied by analyzing the local friction in the bearing. A new model for evaluating bearing temperature is set up treating the contact surfaces between rolling elements and raceways as moving heat sources. Using this model and finite element method, friction power loss and operating temperature of the high-speed angular contact ball bearing in high speed electric spindle system is studied. It can be found that the maximum heat generation and temperature rise of the ball bearing located the inner raceway where the surface damage occurs easily.

Small Rotated bypass unmanned aerial vehicle (UAV) is a relatively new type of unmanned aerial vehicle (UAV), which developed rapidly in recent years. It is an important issue that how to transform tactics requirements for the unmanned aerial vehicle into the parameters of the unmanned aerial vehicle in the field of rotated bypass unmanned aerial vehicle study. This paper aimed at analyzing and confirming the main parameters of the unmanned aerial vehicle, and then to choose the most appropriate model of alternative airfoils on the basis of the main parameters, by using Profili2.21 and comparing the main indicators of airfoils.

At present, exploration depth of Uranium resources is about 300-500 meters in China. It is difficult to explore the resource accurately under 500 meters. A new 3-D resistivity measuring method based on distributed system was proposed in this paper. By changing the power supply electrode and introducing “E-SCAN” observation pattern, the method can be put in pole-dipole, dipole-pole and dipole-dipole measuring mode, finally, apparent resistivity data can be acquired. This article adopts an evaluation method in which A-Kind method was combined with linear weighted method to evaluate measurement uncertainty of the resistivity measuring method. And the results of 3-D low resistance object exploration show that resistivity trends of the method in this paper is highly consistent with multi-function digital DC IP instrument WDJD-2 and Supersting R8 which are widely used in actual measurement. The maximum test error among the method and the two instruments(WDJD-2 and Supersting R8) is 6%. And the repeated average relative error is 3.90%. Besides, the result of 3-D inversion proves the method can be applied to explore the resource accurately with a large depth.

Based on the presentation of features of AADL(architecture analysis and design language) model and Fiacre(intermediate format for the architectures of embedded distributed components) model, a method that transforms AADL model into Fiacre model is proposed in the paper. Firstly, transformation of meta-language is achieved by constructing mapping rules at semantic layer. Program entities of Fiacre model are then produced by constructing a model of concrete syntax and defining the meta-language grammar mapping rules. Finally, the signification about model transformation and future works are discussed.

To overcome the instability of 3D body scanning by manual operation on Kinect sensor, such as skipping frame, missing data, and time consuming, an automatic 3D scanning device using a single Kinect sensor is designed in terms of the KinectFusion algorithm. The control system of computer - Arduino controller - motor drive - stepper motor - power supply has been employed to realize the flap motion and the circular motion of Kinect. The efficiency of the scanning has been improved by automatic control. The optimized scanning parameters have been determined via various scanning tests. Compared to the hand-held scanning, the experimental results indicate that the time cost can be reduced, and the quality of point cloud obtained can be improved significantly.

Currently, although many wave energy offshore test site were under construction or had been put into operation in the world, there had been the lack of relevant research about its location selection problem. This paper gives the definition of offshore wave energy test site based on the wave energy industrial process analysis, analyzes its composition, its main function as well as to explore the development model as a basis for future research.

The relationship between ultrasonic nonlinearity and properties of the liner was studied during the whole curing process by ultrasonic transmission method and infrared spectroscopy. Nonlinearity of input instrumentation was minimized by the natural filtering effect of piezoelectric discs and the maximum excitation energy was acquired simultaneously so as to improve the accuracy of the measuring data. The experimental results indicate that in the liner curing reaction at 40°C ultrasonic nonlinearity parameter decreases gradually after a sharp decline, the variation tendency was consistent with the outcome of infrared spectroscopy as the curing degree increase. The research suggests an effective nondestructive approach to detect the curing properties of the liner in a nonlinear ultrasonic way.

As one of key components for deep-sea apparatus, rotating seals' working performances are especially crucial for relative rotating elements. The sealing course in ambient pressure under deep-sea is analyzed,which displays that the excessive friction caused by the ambient pressure and the magnitude of interference are primary causes for seal failure. To further reveal the friction affect, one experimental device called deep-sea imitating apparatus is designed to test the working performances of rotating seal. Testing results shows that the seal is able to work reliably without leaking more than 10 hours in ambient pressure below 30MPa, and verifies the results of theoretical analysis for this kind of sealing structure are effective,which displays that it is available for requirements of deep-sea environment in short periods.

In order to solve the problem of the pipeline airtight detection before production, this paper presents a solution based on wireless communication technique and the double detection and location method. The solution uses the wireless communication module to control two detection vehicle move in the pipeline. At the same time, the system completed the pipeline airtight detection by pressure detection module in the detection vehicle. When the air pressure value mutation, detection vehicle real time positioning and transmits the detection results to the terminal module in the end of the pipeline. The experiments show that the scheme accurate positioning, and can display the real-time detection results. The system has high application value in the fluid conveying pipeline airtight detection process.

In this paper we study a classical problem in differential geometry: gradient estimate for closed starshaped hypersurfaces with prescribed Gauss curvature measure. They are closely related to the differential geometry and integral geometry of convex hypersurfaces.

Curvature measure and surface area measure are the basic notions in the classical differential geometry. They play fundamental roles in the theory of convex bodies. In here, we present the proof of Theorem 2.1 to show that the gradient estimate for closed starshaped hypersurfaces with prescribed Gauss curvature measure can be obtained.

Project construction is one of the most important economic activities. How to dispose construction waste is an urgent issue in the management of city. The traditional method is simple landfill, not only occupy the land, causing environmental pollution, but also waste a lot of resources which can be rational recycling. In this paper, considering the establishment of a reasonable reverse logistics network for construction waste to achieve the recycling, minimize the total cost such as network facilities investment, operation cost, transportation cost and other related costs.

Since the existing track-before-detect (TBD) procedures perform non-coherent integration during several consecutive scans, and the energy accumulation efficiency is low, in this paper, a coherent TBD algorithm is presented. After the echoes splicing and selection, using velocity matching method and DCFT to compensate the range migration and phase shift, a coherent TBD algorithm performs the coherent integration of the targets' information for multi-scan. The performance of the coherent TBD algorithm is analyzed via a series of numerical experiments.

This paper mainly focuses on measuring and analyzing planar directional characteristics of underwater radiated noise originated from vessel targets in the lengthways section. A corresponding mathematic model is presented based on linear array measurements. Combined with cubic spline interpolation algorithm, a data processing and analysis method is brought up regarding sound pressure spatial distribution and directivity in a single plane. The effectiveness of the mathematic model and data-processing method is further verified based on processing and analyzing sea experiment data. The proposed method is simple, practical and reliable. And the analysis results can be further applied in the studies on noise source analysis, identification and far-field feature extrapolation for underwater radiated noise.

In this paper, we put forward a computer simulation tool to study the structural damage and loading of rock under compression; the process of uniaxial compression and triaxial compression experiments were simulated at room temperature, the rock samples internal stress distribution laws were analyzed, and the influences about confining pressure on the rocks under loading situation were shown; from internal cracks to total disintegration. The whole process of compression deformation of the rock was simulated by using displacement load mode, the distribution law of equivalent plastic strain and axial stress in the rock samples were studied, and verified to further study the deformation and failure characteristics of rock specimen under complex experimental conditions. we found that the compressive strength of rock under confining pressure increased, with the confining pressure. Moreover the form of plastic yielding zone form was consistent with the uniaxial compressive.

A proposed garden site of the Lanzhou City is located in the leading edge of the slope of the ditch and alluvial terraces. It has poor stability after it is transformed into a artificial slope about 35m high which will bring immeasurable loss once it is unstable. Therefore, using Slide software, this paper establishes a model to calculate the slope stability and applies the limit equilibrium theory to analysis of the slope stability quantitatively. However, the results show that the slope is in a less stable state which can not meet requirements of the specification. So the paper analyzes and optimizes the slope stability using Slide calculation module and puts forward the corresponding optimization solutions. When taken reinforcement measures and conducted Slide model again, the stable coefficient is 1.318, which can met the requirements of the slope stability.

Dual-phase lagging model is the important supplementary theory for heat conduction knowledge system, which lies in the introduction of heat flux relaxation time and temperature relaxation time. This article aiming at getting the numerical solution of DPL equation, adopts the central difference method to discretize the 1-D space coordinate and applies the finite element method to transform the difference equation into matrix form. Then the numerical results are derived through multiple iterations by Matlab. The resulting simulation indicates that the value of heat flux relaxation time decides the difference between single-phase lagging model and temperature relaxation time influence the heat propagation velocity to some extent.

Water hammer effect always cause excessive pressure and stress which will endanger the whole string system, for example fatigue damage, wear and tear damage and cracking damage. During well startup or shutdown, instantaneous changes of tubing's internal pressure will bring water hammer effect, so cause acute tubing vibration. So far there have few literatures to make quantitative analysis for the vibration caused by water hammer. This paper introduces improved four equation model analysis which can analyze water hammer effect accurately. According to the field experiment data, comparing the difference of vibration degree between the moment of water hammer effect and non water hammer effect. By finite element software this paper achieves vibration model diagram, natural frequency, and the stress distribution at dangerous moment after vibration acceleration is forced to the model. Finally taking stress as evaluation index to evaluate the safety of completion tubing under water hammer effect. The results show that, with water hammer effect completion tubing vibration is more intense, and occur destructive resonance easily, even cause plastic deformation of tubing.

The efficiency of air-lift artificial upwelling for deep ocean water is simulated with a simplified computational fluid dynamics (CFD) model of two-phase flow in an upward pipe. The model is based on the momentum transfer between the two phases and computations are carried out in a transient way. In addition, phase distributions, pressure, velocity profiles along the axial coordinate and the volumetric flow rates for two phases are presented and calculated in the stationary state. The influence of the pipe diameter and pipe length on the air-lift efficiency is studied and found to be significant. The lifting efficiency increases with the increase of the pipe diameter and the reduction of the pipe length due to the reduction of the wall friction influence on the flow.

The PM2.5 emissions characteristic of vehicle engine fueled with petrol was studied. A test system was established by KHS-PMA PM2.5 real time tester and PM2.5 collecting device. Based on the test system, the variable instrument placement study including top, middle and bottom were carried out under the idle conditions. The test results showed that the mean concentration in the exhaust gas collecting device for PM2.5 was 30 micrograms under the net box detection. The PM2.5 real-time concentration increases at first, then with the time prolonged, the real-time concentration decreased. The final test results showed that the measured maximum concentration of PM2.5 was obtained when the detector was arranged in top of exhaust gas detection box.

Large passenger hub station is the intersection of all kinds of transportation and a complex transportation system, regional hub station is the transition region connecting the internal passenger hub and city, the establishment of good road network station traffic organization is an effective way to improve the efficiency and reduce the traffic congestion in Station passenger transport hub. This paper analyzes the ability of Beijing South Railway Station area traffic network and three kinds of traffic ways which are railway transportation, subway transportation and urban public traffic transportation.

In order to get and analysis the passenger flow information timely and accurately, this article introduces a passenger flow detection system applied at the subway station. The system uses video analysis method based on the depth information, realizing the detection of the real-time passenger flow and extracting the parameter of passenger flow. After image preprocessing, background segmentation, target detection and tracking, the extraction of traffic parameters and other function modules, the pedestrians detection program of system gets and then sends passenger flow parameter information, and later the data receiver program of system receives the passenger flow parameters and finishes data storage management. After debugging when used at a transfer of Beijing subway station, the system can get and save passenger flow parameters timely and accurately.

Galvanic corrosion will happen when the top coating of aluminum alloy joint-structures which abound in the aircraft damages. The corrosion type of aircraft materials is atmospheric corrosion that is the electrochemical corrosion under the thin layer electrolyte. The electrochemical properties of the materials covered with the 0.5mm thick film by self-made electrochemical measurement device have been researched in this paper. The potential distribution and corrosion rate of lap joints after the coating damaged have been calculated by BEASY. The simulation results show that the closer to the bolts, the greater the current density of aluminum alloy, the faster the corrosion rate; the corrosion rate is closely related to the coating damage area, the smaller the damage area, the bigger the corrosion rate in the region of coating damage.

Shape memory alloy is a thermomechanical coupling phase transformation material of multi-scale effect. Its deformation is path-dependent and may involve macroscopic instability. This paper reports the experimental results of deformation evolution of superelastic NiTi shape memory alloy mictotube subjected to displacement-proportional combined tension and torsion. We completed a series of tests focusing on both the stress-strain response and surface morphology of the microtube specimen. The experimental result comprehensively illustrates the deformation behavior of the material. This research is important for the study of the constitutive relation of this kind of material.

The resource of iron ore in our country is relatively deficient. It can not meet the demand of economic development. Every year, large amount of iron ore is imported to meet the demand of metallurgy production. The grade of iron ore in our country is relatively low. Most of the iron ore need to be enrich, so that it can satisfy metallurgy ironmaking production. During the beneficiation process, the resource utilizing level is low. And the grade is high in milltailings. And the recovery rate of metal is low. Especially, the grade of hematite in milltailings is 11—20%. Therefore, reducing grade of tailings is one approach of increasing resource utilizing level. This article analyses the grade factor that the concentrator impacts tailings. Presents a measure to reduce the grade in tailings.

Effect of vortex cavitation in the different of cavitation treatment time, turbine outlet pressure, and solution temperature on the residuals of SO₃²⁻ and Ca²⁺ in the sugarcane juice clarified with sulfitation process was studied in the paper. The experimental results showed that the vortex cavitation can enhance the reaction of SO₃²⁻ and Ca²⁺ to the precipitation of CaSO₃, and reduce the residues of SO₃²⁻ and Ca²⁺ in the sugarcane juice effectively. The longer cavitation treatment time, the lower residuals of SO₃²⁻ and Ca²⁺ in the sugarcane juice; The greater turbine outlet pressure, the lower residuals of SO₃²⁻ and Ca²⁺ in the sugarcane juice; The greater solution temperature, the lower residuals of SO₃²⁻ and Ca²⁺ in the sugarcane juice.

Real time, continuous and high precision navigation service is needed due to the continual geostationary satellite (GEO) orbit maneuver. How to recover orbit rapidly for GEO in Beidou system (BDS) based on short-arc tracking is the key factor. A new orbit determination method uniting data before, among and after maneuver is researched, C-band transfer ranging data and telemetry and telecontrol parameters during satellite maneuver are used together. The results based on observation data for GEO in BDS indicate that: the integrated solution strategy of orbit parameters and thrust force parameters needs to be adopted in the period of orbit recovery. The 2-hour orbital prediction accuracy of 3-dimensional positions is 30m-level, orbital precision in radial component is better than 3m 2 hours after orbit maneuver. It's a solution to resolve several problems of dynamic orbit determination and point positioning in short-arc tracking.

Quadruped robots which can be utilized in the field of rescue, exploration, and entertainment have the characteristic of adapting to different kind of terrain. But raising the speed of them can be intricate. Researchers have developed many kinds of leg-wheel hybrid robots to solve this problem. Traditional leg-wheel hybrid robots always have separated legs and wheels. Obviously, wheels move faster than legs, but smooth ground won't always appear in nature world. Wheels may just be used occasionally. So, we introduce a design of Leg-Wheel hybrid mobile platform which includes a leg-wheel transformation mechanism. It is much more efficient than the separated mechanism. This kind of leg-wheel robot has compact structure. The place for redundant electrical elements can be saved, that means the weight of robot can be reduced incidentally. Also, the design of control system and movement simulation is reported.

Spacecraft pipeline is an important part of the spacecraft, the precision of the pipeline system, development cycle and reliability directly affect the reliability of the whole satellite and spacecraft. In this paper, according to the characteristics of the spacecraft pipeline, designed a remote control system of flexible assembly platform, applying Zigbee technology, and realized the data communication between the upper computer and the assembly robot (three coordinate locator). Pipe assembly robot in the platform can be controlled remotely, making space pipeline assembly platform more convenient, efficient and reliable, further shortened the spacecraft pipe assembly cycle, improve the accuracy and reliability of the pipe assembly.

There has been a significant change to the domestic loads in recent years. With power electronic technique being more and more advanced and popular, an increasing number of domestic electrical appliances adopting power electronic devices are used and connected to low voltage distribution networks, which raises the harmonic level, resulting to a negative impact on the power quality. In this paper, domestic loads are classified into different categories according to simplified circuit topology. Furthermore, suggestions on how to improve power quality in networks are put forward.

In this paper, a novel power stability control measure using the balance resistance and the thyristor controlled series reactor is designed. It can satisfy the power stability requirements in the electric arc furnace. Analysis points out that thyristor controlled series reactors could not reduce the power fluctuations effectively especially when power drops. When cooperating with the balance resistance, the power fluctuation can be reduced significantly. By adjusting the firing angle of the thyristor and the switching time of the balance dynamically, the power fluctuation reduces. Later, an appropriate control strategy is proposed briefly to meet the requirements of fast and accurate adjustment. After that, a simulation result based on PSCAD/EMTDC shows that the new control measure has a good effect to reduce the power fluctuation.

According to the technological requirements of once formed rope making and pretension, this paper presents a control system based on a Siemens S7-200 PLC, in which stretching-compression force measurement transducers measure the strands tension, and information is transmitted based on Modbus protocols among several frequency converters. It is a full-digital, online pretension, and cooperative control system, which is advanced and innovative.

At present, solar collectors thermal performance testing system based on PID control algorithm was defective. In order to improve the system, a fuzzy predictive control algorithm was proposed. Firstly, the fuzzy control and predictive control were combined to adjust the actual system. Secondly, SIMULINK software was applied to establish a PID algorithm for the simulation model which was based on control algorithm and fuzzy prediction. The simulation showed that the fuzzy predictive control method was a feasible and effective approach that can improve the stability of the temperature and speed up the response speed. In the end, this novel method can improve the detection efficiency of the system.

For a class of uncertain Singular linear systems with time-invariant parameter uncertainties, the output feedback robust control hard problem is resolved. A sufficient condition for the solvability of the problem and the output feedback robust feedback controller were obtained in terms of liner matrix inequalities. The result deepens content of robust control theory, and it simplifies some past methods. The designed controller guaranteed that the closed-loop systems was regular, causal, stable for all admissible uncertain parameters under some conditions. A real project simulation example was given to demonstrate the effectiveness of the proposed method.

The application of non-specific voice identification technology has been studied in the smart home system. Combining with the related technologies and features of Internet of things, the voice control system of smart home has been designed. The mobile terminal control system (supporting Android and IOS systems) and embedded portable voice controller are made up of the system; the voice cloud technology is adopted in mobile terminal control software, the embedded portable voice terminal is designing by the systematic framework of LD3320, STM32 and CC2530, combining with IEEE 802.15.4 protocol. The practice verifies that the voice control system implements diversified and comprehensive voice control for controllable devices in smart home.

Robot milling process is an important development direction of robot technology, and the automatic tool path generation method is the key step of it. In this paper, an improved CC route method is presented to generate the tool path based on the geometric development platform of Open Cascade. By adjusting the distance of constrain planes dynamically, the inhomogeneous problem of traditional CC method is avoided and the robot milling precision can be improved. Based on the above, a corresponding CAM system is developed. Tool path of rough and fine milling process for free surfaces can be generated through this system. At last, the feasibility and precision of this method are validated by simulation and experiment.

Biaxial synchronization controller of mechanical system is designed that achieves two groups of transducer-motors track the input signal with zero error in finite time. The whole system generates desired contours even in the presence of disturbances.

In this paper, authors studied the deep sea control systems in underwater oil and gas production facilities, monitored their performances, and put forwarded a hydraulic model to test operational readiness of low-pressure electro-hydraulic control valve for routine maintenance. Results shown that low-pressure electro-hydraulic control valve may open and close properly when supply pressure of valve maintained at 207bar. However at 90bar low-pressure electro-hydraulic control valve may reset itself automatically, and leading to closure when supply pressure is reduced to 30bar. Hence, the experimental conducted shown that low-pressure electro-hydraulic control valve met the standard requirement of subsea control module (SCM) operated under deep-sea condition for deployment in offshore oil and gas exploration.

Reinforcement materials were evaluated with respect to effect on sod strength for different seeding densities. Evaluations were performed using sample plantings in a greenhouse setting. For determining suitable reinforcement materials, was conducted on native grass species for three of those ecoregions. The initial evaluation for determining native grass species was performed using species from six different ecoregions of California. Basic species evaluation was done using biomass, species abundance, and total ground cover. The objective was to evaluate a number of native grass species and reinforcement materials for their suitability for contributing to a harvestable multispecies sod for roadside rehabilitation.

Based on the classical control theory, this paper proposes an adjustable speed motor control model with minimum ripple effect. This feasibility study was conducted and simulated in Matlab using three typical input signals: the unit step, unit speed and acceleration. The simulation results shown that, the minimum ripple controller could ensure the speed of the electromagnetic speed control motor followed the expected speed in the shortest sampling cycle, to achieve the steady-state error of the system to zero. However, it only follows a particular input signal and therefore when the input signals vary, the controllers need to be calibrated separately to follow the signals, hence, with an electromagnetic adjustable speed motor, it is feasible to control a thin coal seam electrical traction shearer with minimum ripple effect.

Because of the psychological needs and personal care requirements of elderly people, a pet-type robot was developed to provide psychological comfort and care for the elderly. The pet robot consists of a control system and a series of function modules including voice recognition, communication, information exchange and others. Supporting software system was developed based on robot functions and hardware information. The robot has a lovely panda shape as its appearance and a user-friendly voice. Together with daily reminders, a gas alarm and other convenient functions, the robot can alleviate loneliness and anxious feelings of the elderly, so to achieve its goal as a psychological rehabilitation aid.

The condensate depression control is a core component in condenser design, that could have a major impact on the rotation speed of cooling water circulating the pump. It is worth taking notes that while the steam discharge from the turbine varying by a large margin, the controller of condensate depression when devised inappropriately, can result in the rotation speed of the cooling water circulating pump accelerating from a leak, to trigger the galloping danger which have to be avoided at all costs.

In this paper, we conducted a study to compare and contrast three control techniques; namely conventional PI control, fuzzy PI control and fuzzy control, and concluded that fuzzy control system that integrated both the conventional PI control and fuzzy PI control in one unified system provides the most stable system, that allow system to switch between the fuzzy controller and the conventional PI controller based on the changing conditions of the turbine.

Electronic Stability Programs (ESP) plays a significant role in improving vehicle safety. However, the development and calibration of ESP control strategy need a long time, as vehicle is a nonlinear and time-varying system. Fuzzy control is robust and does not need accurate mathematical model of control object, so it's suitable to apply fuzzy control to ESP. Based on fuzzy control, this paper proposes a kind of ESP control strategy. According to the current vehicle response characteristics, fuzzy controller decides the desired yaw moment. Pressure controller calculates the corresponding target pressure and controls the hydraulic control unit so that the braking pressure will follow the target pressure. In order to verify the effectiveness of proposed control strategy, double lane change test is carried out on hardware and driver-in-loop test bench. The simulation results show that the proposed control strategy can significantly improve the vehicle handling and stability.

In order to make family life more comfortable, safe, intelligent, good home control system is essential. The ZigBee technology is adopted to set up a home wireless network. The embedded home gateway platform is constructed using ARM Cortex-A9 processor and Android operating system. The Android-based WEB server and client software are developed. Users can log in smart home control system Web server via the Internet or Android phone of installed smart home control client software to control home state and to get the latest home status anytime and anywhere. Meanwhile, in order to improve the measurement accuracy of the system and reduce the false alarm rate, the batch estimate data fusion algorithms based on single sensor are used. Experimental results show that the system can achieve security alarm, indoor environmental testing, home appliances control and intelligent lighting and other functions. The false alarm rate is low.

A wireless control system based on FPGA is designed and implemented, which uses LCD touch screen as a touch and display device, wireless module NRF24L01 as a communication device. The system makes use of the convenience of FPGA in building embedded processor and its peripheral circuits. Experiments demonstrated that the system can be used for real-time remote control and monitoring.

For the mounting plate of height control value, the weakest area is the preload joint surface. It's impossible to test the dynamic stress of preload joint surface directly by current technology. Within this article, the method of defining the suitable parameters for the finite element contact model and the finite element model of the altitude valve's mounting plate were built. By the harmonic response analysis, the dynamic nature and the transitive relation between the preload joint surface and the testing point were collected. From the finite element's result and the test data, the transitive relation was corrected, then the calculated dynamic data of the preload joint surface can be generated and the figure life of the mounting plate of height control value will be assessed finally.

Isothermal die forging is one of the near net-shape metal forming technologies. Strict control of billet temperature during isothermal die forging is a guarantee for the excellent quality of final forging. In this study, a strategy is proposed and optimized to accurately control the billet temperature based on the response surface methodology (RSM). The optimized control strategy is accomplished by employing the thermal compensation during isothermal die forging. The thermal compensation to die is designed to overcome the inevitable heat loss during forging. i.e., the layouts and opening time of heaters, which are assembled on dies, are optimized based on the RSM. Comparisons between the optimized and conventional die forging processes indicate that the proposed strategy can effectively control the billet and die temperature within the designed forming processing range, and guarantee the quality of forging.

The deformation control of surrounding rock of large-span tunnel in soft rock has become a great concern. Combined with an engineering practice, two methods including benching tunnel method and intermediate wall method have been studied and numerically simulated using the ANSYS software. The stress and deformation of surrounding rock caused by the tunnel excavation under different construction methods have also been analyzed, which hopefully, will provide a better insight in construction of tunnel. It is found that as a result of the existence of median septum and which supports the upper load from the soil to a certain extent and the vault vertical displacement is reduced. As for benching tunneling method, the vertical displacement is larger. Accordingly, when CD method is adopted, the surrounding rock stress is minor.

As an effective technology in enhancing oil recovery in low permeability reservoirs, CO₂ flooding has been playing an increasingly important role in world energy exploration. However, serious gas channeling is one of the direct restrictions to oil production. To improve the research of controlling factors and their influence of CO₂ channeling, we will present a geology model according typical low permeability reservoir, which include the influence rules to gas channeling, gas channeling-path dart-coefficient, thickness and type will be analyzed respectively.

Intranet-based testing is an essential part of computer-based college English teaching system. This paper presents the design and implementation of an intranet based test system used in a college for the testing of English. The system was designed to generate test papers on request, assess and mark the tested papers automatically, manage and organize the test results for administrative purposes. The system was implemented in ASP and SQL Server 2005, and successful deployed in the college to provide the college to conduct English test from the generation of test questions to the test results and analysis.

A design scheme of the thermal infrared camera is provided based on the gigabit Ethernet. The conversion of thermal radiation signal to electrical signal is achieved with the utilization of Tau 640. And then, the output image data are converted into a continuous, low-latency IP packet by the Ethernet module. Lastly, the detailed infrared temperature images are displayed after the signal processing on the host computer. The data transmission rate and the point-to-point data transmission distance of this system can be able to reach 1 Gb/s and 100m, respectively.

The application of color in information graphics is important and useful. When compared with text, color not only brings richly visual enjoyment to readers, but also transfers a great quantity of information quickly and effectively. In this paper, we integrate the pattern of information transmission in nature, which is color union and color comparison, into our analysis. This pattern has been used to illustrate the importance and effect of color in information graphics. Concrete examples with special color are used to show the efficiency of information transmission through color.

This paper researches on the planning of high-voltage distribution network for urban area, systematically analyzes its characteristics and reliability, and establishes the mathematical model which takes the minimum annual cost as the objective function. In addition, the rough set theory is introduced into the ant colony algorithm, and the paper takes one urban high voltage distribution network planning for the empirical analysis. Through example analysis and the optimization results of reliability test, the proposed method is proved to be scientific, reasonable and effective to optimize the distribution network programming.

The development phase of simulation integration was summarized, and so on with the key technologies in simulation fields, such as DIS, HLA, DDS, Corba, and Web. The guide thinking of each phase is analyzed, and the main technology requirement focus on the real-time, scalability, and interoperability. The trend of simulation integration in the future is figured out, which were the SOA implementation with QoS guarantee, interoperability between the simulation systems and the physical systems, and along with the system integration based on QoS and interoperability.

With the development of comprehensive mechanized coal mining technology, emerging technology has been applied to more and more coal mining automation. So does the digital image processing technology. The rapid development of image processing technology has been widely used in various fields. The particle aims at the actual situation of coal mine working face, combines with digital image processing technology, and discusses the coal mine working face of the digital image processing technology. It brings the image threshold segmentation, histogram equalization technology into the coal mining face automation system.

Transaction scheduling algorithm is to establish transaction scheduling model contact feedback the relation of transactions, and converts it into an equivalent graph coloring problem, vertex shader graph, in order to achieve a scheduling conflict issues. Compared with the general graph coloring method is the use of different colored nodes to achieve ideological transaction scheduling. The scheduling algorithm is applied to solve practical problems in the current widespread use of RFID technology in the Internet of Things reader conflict in scheduling. By scheduling algorithm can solve the conflict and increase equipment reliability.

The seismic behavior of solid-web steel reinforced concrete (SSRHC) cross-shaped column was investigated through low cycle reversed loading experiment of 4 column specimens with various axial compression ratios, steel ratios and loading direction. The failure process and pattern of column was recorded. The load-displacement hysteretic curve, skeleton curve, stiffness and strength degradation, ductility, energy dissipating capacity were analyzed. The results show that the failure mode of SSRHC specimens with large shear span ratio is bending failure. Research results indicate that SSRHC have favorable ductility, plastic deformation and energy dissipation capacity.

How to extract useful information for the user from the plethora of social networks has become a very difficult problem. To solve this problem, proposing a collaborative filtering algorithm based on the characteristics of social network users. Firstly, according to the characteristics of Internet users in the social network analysis, user activity and user influence forecast algorithm research from the user angle of feature weights; secondly, the establishment of a user interest model, calculate the most similar to the target user adjacent neighbor set; finally, collaborative filtering recommendation model established social network user characteristics the realization of the social network, processing and utilizing the user characteristic data.

With huge investments in mobile e-government services, a concurrent need to exploring key factors affecting citizen acceptance of mobile e-government services. This study aims to establish a citizen acceptance model from the behavioral perspectives of users. Based on the theory of planned behavior (TPB) and the Technology Acceptance Model (TAM), the study proposes an intergraded model for measuring citizen acceptance of mobile e-government services. A web-based survey is undertaken. Based on Partial Least Squares (PLS), the parameter of the model is estimated and goodness-of-fit is found. The results show that the important determinants of citizen intention of mobile e-government are perceived usefulness, perceived ease of use and perceived convenience.

This paper explores how to successfully obtain the body silhouettes and dimensions when people are measured wearing daily clothes in natural environment, proposes the method of “curve segmentation – extraction of effective feature points – curve fitting” to make body silhouette curves reappear on the premise of somatotype, gets the rule of the body silhouette curves through contrasts between the fitting curves and the body silhouettes, then calculates last dimensions which can be used in apparel design and manufacture, and makes recommendations in dressing and gestures for measurement.

In this paper, we perform a feature analysis of a three-dimensional data, which is constructed from Functional Independence Measure (FIM) score of inpatients of a rehabilitation hospital, by applying the Tucker-2 model. Since this analysis method can combine multiple characteristics extracted from the data, a more detailed analysis can be performed. We took up the normal Tucker-2 decomposition and the nonnegative Tucker-2 decomposition as the Tucker-2 model, and compared the analysis results obtained from both decompositions. From the comparison, we saw that distinct kind of characteristics was obtained by the two decompositions. Because of that, it was considered that a multifaceted analysis could be performed by use of both decompositions together.

In the urban road network, urban road intersection is a major bottleneck in the urban road network capacity and traffic capacity. Ensure the orderly and smooth running of urban road intersections, and to improve urban traffic conditions is important. Nongye Lu and Wenhua Lu intersection as the two main roads cross the intersection, Zhengzhou, congestion is very serious.

Over the years, there has been the intersection traffic congestion problems, delay time and serious environment pollution etc.. In order to ease the traffic tension, improve the efficiency of road and facilitate travel, it is necessary to spend time and effort to study the intersection. This paper takes the city road intersection as the breakthrough point, through field survey, through the relevant calculation, idea and scheme is proposed to improve the hardware facilities, bypass shunt. In order to solve the congestion problem in the intersection.

In large-scale urban adaptation and real estate development process, some protective cultural relic buildings and modern excellent architecture face the reality of being demolished, that will generate a large number of construction rubbish, pollute the environment, at the same time, cause a large number of resources waste. In this paper, the application of monolithic moving technique of building is introduced, which can not only save nature resources, but also maximum reduce pollution to the environment.

Fly swallow type arch bridge is now increasingly accepted, because it has the advantages of spectacular shape, large span ability, high bearing capacity, no-thrust arch structure, strong adaptation ability of foundation and etc. But in the construction process, there is error between design and construction work, which results in abnormal force performance of the structure, then lead to the safety of the bridge. With the fly swallow type concrete-filled steel tube arch bridge of Shenzhen Bay as the engineering background, the space mechanical characteristics of the arch bridge were analyzed through the finite element method, which evaluate the static and dynamic characteristics of the structure and the structural stability of construction process as well as the finished bridge. The calculation results and analysis show that the main arch ribs and side spans section can satisfy the requirements of bearing capacity of the structure. As a result, the static and dynamic performances of the arch bridge structure are good, which meet the design specification requirements. Fly swallow type arch bridge embodies the times flavors of modern bridge, it provides new ideas for large span curve special-shaped combination arch bridge.

In this paper, one kind of fabricated concrete frame, which releases the constraint of foundations and joints, was proposed as one of the self-centering and rocking structures. A model of cast-in-place and the other of prefabricated concrete frame were established using finite-element software ABAQUS. Force-displacement hysteresis curves, the Von Mises stress cloud, skeleton curves and stiffness degradation curve were analyzed by contrast under monotonic and low-cyclic reversed loading. The results show that the prefabricated frame, which releases restrictions, has a self-centering and rocking capacity; compared with the cast frame, the precast one is weaker in bearing capacity and energy dissipation capacity, but superior in the decrease of the residual deformation and the damage of components in the meanwhile, which can make a contribution to the reduction of losses and restorations after the earthquake. This paper is aimed mainly at the numerical analysis on seismic behavior of precast concrete frames.

A series of aerodynamic experiments with different opening conditions on a building model with arch roof are conducted to measure the surface and internal pressures simultaneously. To explore the extreme wind loading for these partial enclosed buildings a ‘net pressure’ concept are adopted. The study found that the combination between surface pressure and internal pressure will cause the extreme wind loadings. In addition, the relative angle between the opening and incoming flow is a very important factor to determine the internal pressure to be positive or negative. In particular, in one opening case which faced to incoming flow will cause the sever wind net pressures on roof corner due to the positive internal pressures and corner vortex. However, the net pressures will go down as the second opening appeared. After comparing the results, it also found the net pressure acting on the roof corner which calculated from mean experimental external pressures data combined with gust factor and internal pressure coefficients suggested by building code will be underestimated. Therefore, the safety factor should be increased up to 2.5 to prevent the failure of joint connection between roof and frame at corner.

In this paper, taking into account the effect of the stress wave, the ABAQUS finite element analysis software was used to carry out the simulation for the dynamic buckling of metal bar under axial step load. The bifurcation of strain time-history curve of the symmetric elements on the top and bottom surface of a metal bar were used to verify the critical buckling time, the critical buckling load and the modal graphs are obtained. Meantime the dynamic buckling induced the reflection of the stress wave is also analyzed. The results indicate that the critical buckling load after the reflection of the stress wave is much smaller than the load before the reflection. The longer the critical buckling time, the smaller the critical buckling load.

The current situation of groundwater post-processing produced by High-rise building foundation pit construction in Xuchang city was studied by field investigation, which certified that the present situation and problems of groundwater waste was very serious, the post-processing system of groundwater was put forward based on existing problems correspondingly. This paper put forward suggestions and measures for protection of limited groundwater resources, accelerate the sustainable development of Xuchang city, improve the Xuchang natural ecological environment, accelerate the construction of ecological civilization and social civilization has important guiding significance.

Through summarizing the more mature the embankment filling scheme, backfill scheme, foundation treatment, the coastal belt of tidal flats in wenzhou soft soil foundation treatment effect analysis and evaluation, than choose beach reclamation soil solution and subsequent foundation treatment methods, objective science put forward technically feasible in wenzhou region, economically rational, the optimal scheme of a relatively short time limit, for the construction of the coastal belt tidal flats and tidal flats of the backfill and foundation treatment provides referential experience.

A one-third scale, five-story steel staggered structure with Pratt truss was tested under cyclic loading firstly to study the seismic performance of this structural system. Based on the test results, the failure mode, as well as its bearing capacity, ductility, stiffness, and energy absorbing ability, were obtained. At last, conclusions and suggestions were put forward for design based on the results of experimental results.

Based on the test results of a one-third scale, five-story steel staggered structure with Pratt truss under cyclic loading, a finite element (FE) model was established and verified by comparing the numerical results with test ones. In general, they agreed well. After that, a series of 18-story Pratt truss buildings were designed, and numerical analysis was carried out by using the FE model to study the influences of some main parameters on seismic behavior of this structural system, including height to width ratio of building, aspect ratio of truss, height to width ratio of open-web panel, and truss arrangement in ground floor. At last, conclusions and suggestions were put forward for design based on the results of numerical analysis.

The projectile into concrete targets was simulated by the nonlinear finite element software ANSYS/LS-DYNA3D. The penetration process of the projectile to target board was analyzed, Velocity and acceleration curves were analyzed based on different penetration velocity. The rules of the penetration process were obtained. Residual speed of the projectile penetrating steel fiber plate and shelter plate projectile was compared. Results of the study indicate as followings: material parameters of the projectile and target board were reasonable, shelter plate made of steel structure of steel fiber concrete can lower projectile speed obviously and quickly, and it has better anti-penetration ability.

In this paper, in order to understand fully the hysteretic behavior of carbon fiber reinforced concrete column under low frequency cyclic loads and provide a reference for the application of practical engineering, 3 test specimens have been investigated. Concrete strength grade is C30 and the volume fraction of carbon fiber is 2‰. Then we can get the hysteretic curve and skeleton curve of the column when the axial compressive ratios are 0.4, 0.5, 0.6. In order to get the stress nephogram of the columns, the finite element analysis software ABAQUS is adopted. The change of axial compression ratio has little influence on the full extent of the hysteretic curves. The hysteretic curves under different axial compression ratios are full without significant pinch phenomenon. When it reached the limit bearing capacity, skeleton curve decreased slowly. With the increase of axial load ratio, the ultimate bearing capacity and limit displacement decreased. The simulation curve and experimental curve are in good agreement which proves the rationality of simulation. The carbon fiber reinforced concrete column has good ductility, good plastic deformation capacity and seismic performance. It can be used in practical engineering.

The following section is included:

• Author Index