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Prestressed stayed steel columns (PSSCs) are structural components notable for their exceptional stability and load capacity. However, their behavior under eccentric compression remains poorly understood compared to their performance under axial compression. This study conducted tests and finite element analysis (FEA) to investigate the stability of PSSCs under eccentric compression loading. The study focused on examining the overall stability, buckling modes, and ultimate load capacity of PSSCs under various scenarios. The findings revealed that PSSCs exhibit significantly higher stability and load capacity than conventional columns. However, when subjected to eccentric compression, they experience a substantial decrease in stability. The results of the linear and nonlinear buckling analyses suggest that interactive buckling may occur under certain conditions, thereby influencing the buckling load. These findings clarify the correlation between stability and eccentric compression, offering valuable insights for future research and practical engineering applications.

The applications of triply periodic minimum surfaces (TPMS) in biomedicine, aerospace and functionally graded materials have garnered significant interest. In order to further explore the possibility of regulating the properties of TPMS-based lattice structures, radial-graded Gyroid lattice structures (GLSs) were constructed and Al–Si10–Mg samples were prepared by selective laser melting (SLM). FEA and compression experiments were employed to evaluate the deformation behavior, mechanical response and energy absorption of GLSs. The introduction of the Johnson–Cook model effectively simulated the deformation and failure mechanism of G-777 and G-791, and both of them showed uniform deformation. In comparison to G-777, G-791 demonstrated enhancements of 19.234%, 33.096%, 49.729% and 15.421% in yield strength, plateau stress, elastic modulus and energy absorption, respectively. Meanwhile, the numerical simulation results were in good agreement with the experimental results. The present study suggests the mechanical properties and energy absorption capacity of GLSs can be regulated by radial gradient. This paper can provide a theoretical foundation for customizing the performance of TPMS-based lattice structures.

In this study, using the nano and micro-indentation tests and finite element analysis (FEA), we investigated the fracture behaviors of diamond like carbon (DLC) on silicon in indentation state. Diamond like carbon coating of 3μm and 1.5μm thickness were deposited on polished (100) single crystal silicon substrates by radio frequency plasma assisted chemical vapor deposition (RF-PACVD), respectively. Fracture toughness of DLC films was calculated from the measured lengths of the cracks formed by nano and micro-indentation on each sample. We used various equations such as Lawn's and Liang's equation to calculate the fracture toughness. The effective fracture toughnesses of these DLC films were 1.2 ~1.3 MPam^0.5, calculated by Lawn's and Liang's equations. The true fracture toughness of DLC on silicon, excluding the portion of fracture toughness due to a substrate, was determined to be 4.0~5.1MPam^0.5. DLC films with crack initiation and propagation were analyzed by finite element method.

This paper introduces a new based-on ultrasonic wave micro-fluid driving technique that is different from the present principle. The standing wave is generated by ultrasonic vibration in the device, and acoustic field is generated simultaneously. The particles in fluid medium of the device move towards the node of the standing waves caused by the effect of acoustic radiation pressure. A new device structure has been designed based on piezoelectric drive principle. The vibration modes and response has been obtained by FEA. The simulation results also indicate the feasibility of movements. Considering the influence of vibrator dimension, the dimension of the vibrator has been optimized. The experiment has been accomplished in the device with polystyrene spheres and achieves the enrichment of the particles.

In this study, the interfacial perpendicular crack behavior and stress state of the unidirectional fiber reinforced Metal Matrix Composites (MMCs) are investigated by using FEA under the transverse loading. The fiber assumed as isotropic linear elastic SiC and the matrix is assumed as isotropic elastic-plastic Ti. The fiber/matrix interface is modeled as multi thin layer with different linear material properties. The behavior of perpendicular crack to the interface according to the change of the interface characteristics and thickness are evaluated.

It is important to realize good consistency among different device units on a big wafer. The bad product consistency results from the processing deviation which is hard to control. A novel simulation method to control and reduce the influence of processing deviation on the sensitivity of a piezoresistive pressure sensor is provided in this paper. Based on finite element analysis (FEA) and mathematical integration, the performance of the pressure sensors is simulated. The pressure sensors are designed and fabricated according to the simulation results. The test results confirm that this simulation method can help to design the pressure sensor very precisely. From the simulation and test results, we find that properly enlarging the size of the square silicon membrane can improve the devices consistency.

Micro-Electro-Mechanical System (MEMS)-based pressure sensors operating on the principle of piezoresistivity have found profound application in various fields like automobile, aerospace, aviation, biomedical and consumer electronics. Various research studies have been conducted to optimize the design of MEMS-based pressure sensors to meet specific requirements of different fields. Modification in the structure of the piezoresistors placed on these sensors has shown great effect in this regard. However, most of these improvements have been validated through fabrication and measurement, but there has been a lack of significant studies developing analytical models to explain these improvements. This paper studies the performance of a single-turn piezoresistor design on a square silicon diaphragm. The analytical model relates the dimensions of the single-turn piezoresistor on a square diaphragm to the output voltage, and hence, sensor sensitivity is laid out. The correctness of the relation is also validated through Finite Element Analysis (FEA) performed using COMSOL Multiphysics software. Hence, an optimized single-turn design is presented which achieves a sensitivity of 203.57mV/V/MPa over a pressure range of 0–1MPa. These results are then compared to work from existing literature. The comparison shows an improved performance which was achieved by optimizing the design through its derived analytical model. The proposed sensor can be utilized in disposable blood pressure measurement system where high sensor sensitivity is required.

In this study, the effect of contact pressure on fretting fatigue behavior of Al7075-T6 under cyclic normal contact loading is investigated. It is found that fretting fatigue life for the case of cyclic contact load was significantly less than that for constant contact load at the same axial and contact load levels, particularly for High Cycle Fatigue (HCF) conditions. The results showed that the fretting fatigue life decreased monotonically with the increase in normal contact load for all axial stresses. Examination of the fretting scars was performed using optical microscopy and numerical simulation was carried out using commercial finite element (FE) codes ABAQUS${}^{\text{®}}$ and FRANC2D/L${}^{{}^{\text{®}}}$ to calculate the crack propagation life. The crack initiation life was calculated by a combination of numerical and experimental results. Finally, the FE simulation was validated by a comparison between the numerical crack growth rate and the experimental measurement using replica.

In order to better understand the behavior of the total wrist implant systems, finite element analysis (FEA) was used to model the articular surfaces of two unconstrained total wrist arthroplasty (TWA) devices. After creating models based on manufacturer specifications, simulations of flexion, extension, radial deviation, ulnar deviation and circumduction were run with simulated moments from surrounding tendons under displacement control. In addition, simulations were run under positioning that represented a pronated and supinated forearm as well as unstable conditions. Understanding implant behavior and capabilities as related to the shape of the articular surfaces is important for proper prescription of implants as well as determining future directions for the design of arthroplasty devices.

In this paper, a finite element formulation based on first-order shear deformation theory (FSDT) is used to study the thermal buckling behavior of functionally graded material (FGM) hemispherical shells with a cut-out at apex in a high temperature environment. A Fourier series expansion for the displacement variable in the circumferential direction is used to model the FGM hemispherical shell. The material properties of FGM hemispherical shells are functionally graded in the thickness direction according to a volume fraction power law distribution. Temperature-dependent material properties are considered to carry out a linear thermal buckling analysis. The hemispherical shell is assumed to be clamped–clamped and has a high temperature specified on the inner surface while the outer surface is at ambient temperature. The one-dimensional heat conduction equation is applied along the thickness of the shell to determine the temperature distribution and thereby material properties. Converged critical buckling temperatures are computed for two cases of thermal loads, namely, under uniform temperature rise and temperature gradient across the thickness. Numerical studies include the influence of, power law index, base to radius ratios, and different cut-out angles at the apex on the magnitude of thermal buckling temperature.

The influence of localized corrosion on cementless titanium-alloy modular total hip arthroplasty was analyzed using numerical and stochastic modeling. Corrosion depth influences maximum stress significantly, thereby reducing the load carrying capacity. Numerical analysis revealed that the stress levels due to corrosion in the modular implants are influenced not only by the pit geometry, but also by the contact properties of the taper junctions. Subsequently, crevice corrosion was economically modeled with two parameters related to physical and chemical properties of the materials involved. The solution introduces a dimensionless number that determines whether anoxic conditions will be reached. The analysis confirms the power-law relationship for the exponent variation with the concentration gradient variation assumed by others. The results may be used in averting the progression to rapid corrosion growth through infusion of oxygen in the crevice at the appropriate time intervals. Stochastic modeling of crevice area and maximum depth shows a power-law increase in dispersion measures with exponent of 0.63–0.64 though the average increase follows a more modest exponent of 0.13–0.15. A holistic approach, and continuous research towards the development of robust corrosion models is warranted so as to predict and enhance the design life of otherwise successful modular arthroplasties. A better understanding of the phenomenon may help alleviate early and catastrophic fractures.

This study describes a method for performing transient finite element analysis (FEA) of an assistive device using experimental parameters obtained from gait analysis. A subject displaying pathologic gait, owing to lower limb deformity, was chosen for gait study. Using CAD tools, a remedial orthotic device was designed, which is expected to improve the gait of the subject. The orthotic model was subjected to static and transient loading conditions obtained from gait study, using an FEA tool. The stress ‘hot’ zones between the two modes of analysis are studied. In addition, the experimental gait data of a healthy control group were recorded to perform univariate regression studies for predicting the peak values of the normal forces, and validated by comparing with those available in the literature. The values thus obtained may be used for static behavioral analysis of assistive devices. From the FEA results, it can be conclusively said that the orthotic model is capable of sustaining gait cycle loading. The regression studies suggest the possibility of using anthropometric data to predict gait forces and subsequently perform static and transient loading analysis of assistive devices.

Hip resurfacing arthroplasty (HRA) is a long-established procedure. It is a minimally invasive surgery where the surgical wound is relatively small to facilitate a shorter recovery period. HRA remained a popular option among the patients allowing better range of motion of the joint compared to that of total hip arthroplasty (THA). Although HRA is associated with the above advantages, complications involving femoral neck fractures after surgery still occur. Therefore, the present study attempts to assess the impact of stress under various alignment conditions and different scenarios in surgical errors upon the femoral neck in hip resurfacing prostheses (HRP) that may be encountered during the procedure using finite element analysis (FEA) technique. The results showed that anteversion implantation errors on femoral components should be avoided, and that the main reason that causes femoral neck fracture is related to the stress shielding effect generated internally in the femoral neck. Methods to prevent the incidence of such events are a major obstacle to be solved in the future.

Little is known about why and how biomechanics govern the hypothesis that three-Lag-Screw (3LS) fixation is a preferred therapeutic technique. A series models of surgical internal-fixation for femoral neck fractures of Pauwells-II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Seventeen sets of CT scanned femora were imported onto Mimics extracting 3D models; these specimens were transferred to Geomagic Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; three sorts of internal fixators were expressed virtually by Pro-Engineer. Processed by Hypermesh, all compartments were assembled onto three systems actually as “Dynamic hip screw (DHS), 3LS and DHS+LS”. Eventually, numerical models of Finite Elemental Analysis (FEA) were exported to AnSys for solution. Three models for fixtures of Pauwells-II were established, validated and analyzed with the following findings: Femoral-shaft stress for $c$(3LS) is the least; Internal-fixator stress (MPa) for $a(\mathrm{\text{DHS}})=196.97>b(\mathrm{\text{DHS}}+\mathrm{\text{LS}})=88.37>c(3\mathrm{\text{LS}})=63.81$; Integral stress (MPa) for $a(\mathrm{\text{DHS}})=195.35>b(\mathrm{\text{DHS}}+\mathrm{\text{LS}})=86.72>c(3\mathrm{\text{LS}})=64.60$; displacement of femoral head (mm) for a$(\mathrm{\text{DHS}})=1.068>c(3\mathrm{\text{LS}})=1.010>b$(DHS+LS) = 0.735; displacement of femoral shaft (mm) for $c(3\mathrm{\text{LS}})=0.714>a(\mathrm{\text{DHS}})=0.533>b(\mathrm{\text{DHS+LS}})=0.475$; and displacement of fixators for $c(3\mathrm{\text{LS}})=0.982>a(\mathrm{\text{DHS}})=0.973>b(\mathrm{\text{DHS}}+\mathrm{\text{LS}})=0.706$. Mechanical comparisons for other femoral parks are insignificantly different, and these data can be abstracted as follows: the stress of 3LS-system was checked to be the least, and an interfragmentary displacement of DHS+LS assemblages was assessed to be the least”. A 3LS-system should be recommended to clinically optimize a Pauwells-II facture; if treated by this therapeutic fixation, breakage of fixators or secondary fracture is supposed to occur rarely. The strength of this study is that it was performed by a computer-aided simulation, allowing for design of a preoperative strategy that could provide acute correction and decrease procedure time, without harming to humans or animals.

Regenerative chatter is a major hurdle to the productivity and quality of machining operations. This is because of the undesirable surface finish, excessive tool wear and deteriorated dimensional accuracy. Machining chatter analysis techniques examine the stability of a closed-loop model of machining forces and tool-workpiece system. This model is based on mathematical manipulations of machining forces and the dynamic responses of machining tooling. Almost all techniques derive the dynamic responses from physical test. In this paper, a novel approach of milling chatter stability analysis is introduced by using FEA applications to obtain the dynamic responses of the machine tool. The accuracy of this methodology is validated by machine shop tests.

Electrochemical discharge machining (ECDM) is an advanced machining process which uses both chemical action and spark discharge method for removal of materials. Till date, most of the applications of ECDM are in machining nonconductive materials, although some authors have also tried machining conductive materials. This paper attempts to develop a finite element simulation model based on heat generation in the spark region to evaluate material removal rate (MRR) in case of quartz and soda lime glass. The calculation of MRR is based on melting and evaporation of the material due to high temperature generated due to spark discharge. Convection heat transfer is also considered in the analysis. The results obtained from the simulation are compared with available experimental results and previous simulation results. Although this process is not used in the industry till now, it has a lot of scope for research and development.

Corrosion is a common phenomenon and critical aspects of steel structural application. It affects the daily design, inspection, and maintenance in structural engineering, especially for the heavy and complex industrial applications, where the steel structures are subjected to hash corrosive environments in combination of high working stress condition and often in open field and/or under high temperature production environments. In the paper, it presents the actual engineering application of advanced finite element methods in the predication of the structural integrity and robustness at a designed service life for the furnaces of alumina production, which was operated in the high temperature, corrosive environments, and rotating with high working stress condition.

Industrial transformer is one of the most critical assets in the power and heavy industry. Failures of transformers can cause enormous losses. The poor joints of the electrical circuit on transformers can cause overheating and results in stress concentration on the structure which is the major cause of catastrophic failure. Few researches have been focused on the mechanical properties of industrial transformers under overheating thermal conditions. In this paper, both mechanical and thermal properties of industrial transformers are jointly investigated using finite element analysis (FEA). Dynamic response analysis is conducted on a modified transformer FEA model, and the computational results are compared with experimental results from literature to validate this simulation model. Based on the FEA model, thermal stress is calculated under different temperature conditions. These analysis results can provide insights to the understanding of the failure of transformers due to overheating, therefore are significant to assess winding fault, especially to the manufacturing and maintenance of large transformers.

Large deformation of the elastomer membrane, for separating the liquid and electrolysis chamber in an electrochemical actuator, was simulated using Mooney Rivlin model and finite element analyses. Precision gravimetry experiments were conducted in parallel. The pressure in the electrolysis chamber was monitored during the gravimetry experiments. Experimental results are compared with the simulation and good agreement was achieved.

It was also found that in the initial stage of the liquid delivery, before the membrane touched the liquid chamber bottom, the delivery rate is constant at a constant current. Hereafter, the delivery rate decreased with time. Simulation and experimental observations are also in good agreement.

CEMHYD3D has been employed to simulate the representative volume element (RVE) of cementitious systems (Type I cement) containing fly ash (Class F) through a voxel-based finite element analysis (FEA) approach. Three-dimensional microstructures composed of voxels are generated for a heterogeneous cementitious material consisting of various constituent phases. The primary focus is to simulate a cementitious RVE containing fly ash and to present the homogenized macromechanical properties obtained from its analysis. Simple kinematic uniform boundary conditions as well as periodic boundary conditions were imposed on the RVE to obtain the principal and shear moduli. Our current work considers the effect of fly ash percentage on the elastic properties based on the mass and volume replacements. RVEs with lengths of 50, 100 and 200$\mu \mathrm{\text{m}}$ at different degrees of hydration are generated, and the elastic properties are modeled and simulated. In general, the elastic properties of a cementitious RVE with fly ash replacement for cement based on mass and volume differ from each other. Moreover, the finite element (FE) mesh density effect is studied. Results indicate that mechanical properties decrease with increasing mesh density.