International Journal of Computational Materials Science and Engineering

In this study, a new algorithm for the nonlinear buckling behavior of the stiffened functionally graded graphene-reinforced composite laminated (FG-GRCL) toroidal shell segments in the thermal environment surrounded by the elastic foundation and subjected to torsional load is introduced. The FG-GRCL shell segment is stiffened by the FG-GRCL ring and/or stringer stiffener system. Based on the Donnell shell theory with the Stein and McElman approximation, considering the von Karman geometrical nonlinearity and the anisotropic smeared stiffener technique for FG-GRCL stiffeners, the formulations to investigate the critical buckling load and postbuckling torsional load-deflection curves are determined. A new algorithm is fully developed by adding the effect of circumferential stress into the stress function. The significant effects of temperature, stiffener system, geometrical parameters, and elastic foundation are considered and studied in detail.

This paper discusses the problem of fingero-imbibition phenomenon with magnetic field effect. The problem arises in two-phase flow through homogeneous porous medium during secondary oil recovery process. The mathematical formulation gives us one-dimensional nonlinear partial differential equation. Homotopy analysis method is adopted to solve the governing equation. The solution is discussed numerically and graphically with the help of Mathematica BVPh package.

In this study, three-dimensional thermoelastic behavior of a functionally graded (FG) truncated conical shell with piezoelectric layers perfectly bonded to its inner and outer surfaces under electro–thermo–mechanical loads is investigated. The material properties of the FG truncated conical shell are assumed to be graded along the thickness according to a power-law function while the Poisson’s ratio is considered constant. The differential quadrature method (DQM) is utilized to obtain numerical results. The findings of this method are compared with the results published in the literature and excellent agreement with significantly fast convergence is shown. Parametric studies are performed to demonstrate the effects of the FG grading index, edge boundary conditions, semi-vertex angle of the shell, and thickness of the piezoelectric layers on the distribution of stress components, displacements, and electric potential.

In this paper, a new four-variable refined plate theory for dynamic analysis of stiffened functionally graded composite plates reinforced by carbon nanotubes (SFG-CNTRC) subjected to blast loadings is developed. The governing equations of the system are obtained using the finite element method. The Newmark’s time integration is used to solve the vibration equations for determining the dynamic response of the plates. To check the validity of the present formulation, numerical results are compared with the previous data in the literature. The effects of volume fraction of carbon nanotubes, thickness of the plate, and boundary conditions of the plate on the dynamic response of the SFG-CNTRC are studied.

In this study, we present the hybrid complex variable element-free Galerkin (HCVEFG) method for solving 3D Helmholtz equations. The dimension splitting method (DSM) will be introduced into the corresponding governing equation, thus a series of 2D forms can be obtained by splitting the problem domain of 3D Helmholtz equation. For every 2D problem, the shape function can be obtained by using the improved complex variable moving least-squares (ICVMLS) approximation, and the essential boundary condition can be imposed by using the penalty method, thus the discretized equations of 2D problems can be derived by using the corresponding Galerkin weak form. These equations can be coupled by using the finite difference method (FDM) in the dimension splitting direction, thus final formulae of the numerical solution for 3D Helmholtz equation can be obtained. In Sec. 4, the relative errors are given, and the convergence is analyzed numerically. The numerical result of these examples illustrates that the calculation speed can be improved greatly when the HCVEFG method is used rather than the improved element-free Galerkin (IEFG) method.

Temperature is one important factor which decides the assembly accuracy and reliability of the aircraft. Especially with the development of large-sized aircraft, the small temperature change in the aircraft assembly will result in a large displacement deviation and non-negligible internal stress. Therefore, it’s crucial to characterize and predict the temperature during the assembly process of aircraft. Selecting one type of assembly frame for aircraft wing as the study object, temperature in this structure was measured and recorded for one year. Based on the measured data, a model of an optimized BP neural network is proposed to analyze and predict the temperature distribution. The trained temperature model shows a good result with a relative error of 1% and an absolute error of $2^{\circ }$C. Finally, the displacement of assembly frame is obtained from the temperature distribution.