K. Khanna^1,2, V.K. Gupta³, S.P. Nigam¹

CMC-Computers, Materials & Continua, Vol.48, No.3, pp. 147-161, 2015, DOI:10.3970/cmc.2015.048.147

Abstract A mathematical model is developed to describe the steady state creep in a rotating Al-SiC_p disc having a non-linear thickness profile and distribution of SiC particles along the radial direction. The model is used to investigate the effect of imposing three different kinds of radial temperature profiles viz. linear, parabolic and exponential with fixed values of inner and outer surface temperatures, on the creep stresses and strain rates. It is noticed that by increasing the temperature exponent (n_T), the radial stress (over the entire radius) and tangential stress (near the inner radius) increase in the disc. However, the tangential stress… More >

G. Q. Xie¹, J. P. Wang², Q. L. Zhang¹

CMC-Computers, Materials & Continua, Vol.48, No.2, pp. 103-117, 2015, DOI:10.3970/cmc.2015.048.103

Abstract Small-scale effect on the static deflection of a clamped graphene sheet and influence of the helical angle of the clamped graphene sheet on its static deflection are investigated. Static equilibrium equations of the graphene sheet are formulated based on the concept of nonlocal elastic theory. Galerkin method is used to obtain the classical and the nonlocal static deflection from Static equilibrium equations , respectively. The numerical results show that the static deflection and small-scale effect of a clamped graphene sheet is affected by its small size and helical angle. Small-scale effect will decrease with increase of the length and width… More >

Xing Wei^1,2, Wen Chen^1,3, Bin Chen¹

CMC-Computers, Materials & Continua, Vol.48, No.1, pp. 1-23, 2015, DOI:10.3970/cmc.2015.048.001

Abstract The thermal residual stress in the fabrication of functionally graded material (FGM) systems can give rise to various mechanical failures. For a FGM system under a given fabrication environment, the thermal residual stresses are determined by the spatial distribution of its constituent components. In this study, we optimize a Ni/Al₂O₃ FGM plate aiming at minimizing the thermal residual stresses through controlling its compositional distribution. Material properties are graded in the thickness direction following a power law distribution in terms of the volume fractions of constituents (P-FGM). An analytical model and a hybrid genetic algorithm with the pattern search are employed… More >

Qifeng Fan¹, Yaping Zhang², Leiting Dong^1,3, Shu Li¹, Satya N. Atluri⁴

CMC-Computers, Materials & Continua, Vol.47, No.2, pp. 65-88, 2015, DOI:10.3970/cmc.2015.047.065

Abstract A very simple displacement-based hexahedral 32-node element (denoted as DPH32), with over-integration in the thickness direction, is developed in this paper for static and dynamic analyses of laminated composite plates and shells. In contrast to higher-order or layer-wise higher-order plate and shell theories which are widely popularized in the current literature, the proposed method does not develop specific theories of plates and shells with postulated kinematic assumptions, but simply uses the theory of 3-D solid mechanics and the widely-available solid elements. Over-integration is used to evaluate the element stiffness matrices of laminated structures with an arbitrary number of laminae, while… More >

W. Xia¹, Y.P. Feng², D.W. Zhao³

CMC-Computers, Materials & Continua, Vol.46, No.2, pp. 125-144, 2015, DOI:10.3970/cmc.2015.046.125

Abstract Postbuckling analysis of functionally graded ceramic-metal plates under temperature field is presented using finite element multi-mode method. The three-node triangular element based on the Mindlin plate theory is employed to account for the transverse shear strains, and the von-Karman nonlinear strain-displacement relation is utilized considering the geometric nonlinearity. The effective material properties are assumed to vary through the thickness direction according to the power law distribution of the volume fraction of constituents. The temperature distribution along the thickness is determined by one dimensional Fourier equations of heat conduction. The buckling mode shape solved from eigen-buckling analysis is adopted as the… More >

Chih-Ping Wu, Ruei-Yong Jiang

CMC-Computers, Materials & Continua, Vol.46, No.1, pp. 17-56, 2015, DOI:10.3970/cmc.2015.046.017

Abstract An asymptotic meshless method using the differential reproducing kernel (DRK) interpolation and multiple time scale methods is developed for the three-dimensional (3D) free vibration analysis of sandwich functionally graded material (FGM) circular hollow cylinders with combinations of simply-supported and clamped edge conditions. In the formulation, we perform the mathematical processes of nondimensionalization, asymptotic expansion and successive integration to obtain recurrent sets of motion equations for various order problems. Classical shell theory (CST) is derived as a first-order approximation of the 3D elasticity theory, and the motion equations for higher-order problems retain the same differential operators as those of CST, although… More >

Mohamed I. A. Othman^1,2,3, W. M. Hasona^2,4, Nehal T. Mansour^2,5

CMC-Computers, Materials & Continua, Vol.45, No.3, pp. 203-220, 2015, DOI:10.3970/cmc.2015.045.203

Abstract The problem of the generalized thermoelastic medium for three different theories under the effect of a gravitational field is investigated. The Lord- Shulman, Green-Naghdi III, three-phase-lag theories are discussed with twotemperature. The normal mode analysis is used to obtain the analytical expressions of the displacement components, force stress, thermodynamic temperature and conductive temperature. The numerical results are given and presented graphically, when the thermal force is applied. Comparisons are made with the results predicted by three-phase-lag model, Green-Naghdi III and Lord-Shulman theories in the presence and absence of gravity as well as two temperature. More >

M.R. Akbari¹, J. Ghanbari^1,2

CMC-Computers, Materials & Continua, Vol.45, No.3, pp. 187-202, 2015, DOI:10.3970/cmc.2015.045.187

Abstract Exact analytical solution for functionally graded hollow discs under internal pressure, thermal load and rotation are provided in this paper. Material properties of discs, i.e. elastic modulus, density and thermal expansion coefficient are assumed to vary in radial direction. Two power functions are assumed for property dependency to study various types of functional grading of materials in the discs. Assuming small deformations, a differential equation is obtained and solved for the Airy stress function. The effects of various grading functions on the stress and deformation distribution are studied and an optimum value for the power is obtained. More >

M. Bendouba¹, A. Djebli¹, A. Aid¹, N. Benseddiq², M. Benguediab³

CMC-Computers, Materials & Continua, Vol.45, No.3, pp. 163-186, 2015, DOI:10.3970/cmc.2015.045.163

Abstract This work focuses on a linear elastic analysis by the finite element method and the development of a shape function, commonly known as geometrical correction factor, for the case of semi-elliptical crack in a cylindrical rod. We used the same shape function to analyze the behavior of the rod in the case of a viscoelastic medium materialized by a polymeric material such as HDPE. A linear viscoelastic model calibrated from a relaxation test was developed and implemented in Abaqus. Results showed a relatively good performance, compared with finite element method. More >

Jianfeng Lu¹, Xu Liang^1,2, Shuling Hu^1,2

CMC-Computers, Materials & Continua, Vol.45, No.3, pp. 145-162, 2015, DOI:10.3970/cmc.2015.045.145

Abstract Flexoelectricity phenomenologically describes the universal electromechanical coupling effect between electric polarization and strain gradient, and electric field gradient and elastic strain. In contrast to piezoelectricity which is invalid in materials with inversion symmetry, flexoelectricity exists, commonly, in all solid dielectrics. In this paper, a summary of the research on flexoelectricity is presented to illustrate the development of this topic. Flexoelectricity still have many open questions and unresolved issues in the developing field, although it has attracted a surge of attention recently. Here we review the theoretical investigations and experimental studies on flexoelectricity, and the aim of the current paper is… More >