Michely Laís de Oliveira^1,*, Marcio Augusto Villela Pinto², Simone de Fátima Tomazzoni Gonçalves², Grazielli Vassoler Rutz³

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.2, pp. 251-270, 2018, DOI:10.31614/cmes.2018.04237

Abstract Studies of problems involving physical anisotropy are applied in sciences and engineering, for instance, when the thermal conductivity depends on the direction. In this study, the multigrid method was used in order to accelerate the convergence of the iterative methods used to solve this type of problem. The asymptotic convergence factor of the multigrid was determined empirically (computer aided) and also by employing local Fourier analysis (LFA). The mathematical model studied was the 2D anisotropic diffusion equation, in which ε > 0 was the coefficient of a nisotropy. The equation was discretized by the Finite… More >

Chunguang Li^{1, *}, Cuihua Li^{1, 2}, Cong Sun³, Hong Zheng¹

CMC-Computers, Materials & Continua, Vol.54, No.1, pp. 21-41, 2018, DOI:10.3970/cmc.2018.054.021

Abstract Previous approaches can only tackle anisotropic problems with cohesion varying with direction. A novel linearization of the Mohr-Coulomb yield criterion associated with plane strain problem has been achieved by simulating the Mohr’s circle with orientation lines in σ-τ space, which allows for lower bound solution of soils with cohesion and friction coefficient varying with direction. The finite element lower limit analysis formulation using the modified anisotropic yield criterion is then developed. Several examples are given to illustrate the capability and effectiveness of the proposed numerical procedure for computing rigorous lower bounds for anisotropic soils. More >

S. Slama¹, H. Kahalerras¹, B. Fersadou¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.3, pp. 155-172, 2017, DOI:10.3970/fdmp.2017.013.155

Abstract A numerical study is conducted to investigate the problem of mixed convection of a nanofluid in a vertical porous channel with one wall heated and the other cooled. The Darcy-Brinkman-Forchheimer model is used to describe the flow in the porous medium, considered as anisotropic in thermal conductivity, and the two-phase approach is adopted to simulate the motion of the nanofluid. The governing equations with the associated boundary conditions are solved by the finite volume method. The parametric study is focused on the variation of the Richardson number Ri, the heat fluxes ratio R_q, the Darcy number… More >

A. M. Abd-Alla^{1, 2}, S. M. Abo-Dahab^{1, 3}, Aftab Khan⁴

CMC-Computers, Materials & Continua, Vol.53, No.1, pp. 49-72, 2017, DOI:10.3970/cmc.2017.053.052

Abstract In this paper, we investigated the propagation of the rmo elastic surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order ofnth order, including time rate of strain under the influence of rotation.The general surface wave speed is derived to study the effects of rotation and thermal on surface waves. Particular cases for Stoneley, Love and Rayleigh waves are discussed. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. Our results for viscoelastic of order zero are well More >

CMC-Computers, Materials & Continua, Vol.52, No.2, pp. 123-131, 2016, DOI:10.3970/cmc.2016.052.123

Abstract In this paper, the gyrotropic bi-anisotropy of the chiral medium in substrate constitutive parameters (xc and hc) of a rectangular microstrip patch antenna is introduced in order to observe its effects on the complex resonant frequency and half-power bandwidth. The analysis is based on the full-wave spectral domain approach using the Moment Method, with sinusoidal type basis functions. The numerical calculations related to the dominant mode have been carried out, and it has been observed that the resonant frequency and the bandwidth are directly linked to the medium chirality. The new results can be considered More >

Wenxiang Xu^1,2,3,4, Ganquan Yang⁵, Peng Lan², Huaifa Ma¹

CMC-Computers, Materials & Continua, Vol.52, No.1, pp. 25-40, 2016, DOI:10.3970/cmc.2016.052.025

Abstract Understanding the excluded volume of anisotropic particle is of great importance in the evaluation of continuum percolation and random packing behaviors of soft/hard particle systems in heterogeneous disordered media. In this work, we obtain the excluded volumes of several anisotropic convex particles including prolate spheroids, oblate spheroids, spherocylinders, and Platonic particles, using theoretical and numerical approaches. According to the second virial coefficient, we first present a theoretical scheme for determining the excluded volumes of anisotropic particles. Also, the mean tangent diameters of anisotropic convex particles are formulated by the quantitative stereology. Subsequently, Monte Carlo simulations… More >

Y.C. Shiah¹, C.L. Tan^2,3, Li-Ding Chan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.1, pp. 15-33, 2015, DOI:10.3970/cmes.2015.109.015

Abstract In the conventional boundary element method (BEM), the presence of singular kernels in the boundary integral equation or integral identities causes serious inaccuracy of the numerical solutions when the source and field points are very close to each other. This situation occurs commonly in elastostatic analysis of thin structures. The numerical inaccuracy issue can be resolved by some regularization process. Very recently, the self-regularization scheme originally proposed by Cruse and Richardson (1996) for 2D stress analysis has been extended and modified by He and Tan (2013) to 3D elastostatics analysis of isotropic bodies. This paper More >

Chetan D. Kuthe^∗, R.V. Uddanwadiker^†, Alankar Ramteke^‡

Molecular & Cellular Biomechanics, Vol.11, No.2, pp. 113-128, 2014, DOI:10.3970/mcb.2014.011.113

Abstract Biomechanical researches are essential to develop new techniques to improve the clinical relevance. Skeletal muscle generates the force which results in the motion of human body, so it is essential to study the mechanical and structural properties of skeletal muscle. Many researchers have carried out mechanical study of skeletal muscle with in-vivo testing. This work aims to examine anisotropic mechanical behavior of skeletal muscle with in vitro test (tensile test). It is important to understand the mechanical and structural behavior of skeletal muscle when it is subjected to external loading; the research aims to determine… More >

Z. D. Han¹, S. N. Atluri^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.1, pp. 1-34, 2014, DOI:10.3970/cmes.2014.097.001

Abstract The concept of a stress tensor [for instance, the Cauchy stress σ, Cauchy (1789-1857); the first Piola-Kirchhoff stress P, Piola (1794-1850), and Kirchhoff (1824-1889); and the second Piola-Kirchhoff stress, S] plays a central role in Newtonian continuum mechanics, through a physical approach based on the conservation laws for linear and angular momenta. The pioneering work of Noether (1882-1935), and the extraordinarily seminal work of Eshelby (1916- 1981), lead to the concept of an “energy-momentum tensor” [Eshelby (1951)]. An alternate form of the “energy-momentum tensor” was also given by Eshelby (1975) by taking the two-point deformation gradient tensor… More >

Y.C. Shiah¹, C.L. Tan^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.6, pp. 425-447, 2014, DOI:10.3970/cmes.2014.102.425

Abstract Green’s functions, or fundamental solutions, are necessary items in the formulation of the boundary integral equation (BIE), the analytical basis of the boundary element method (BEM). In the formulation of the BEM for 3D general anisotropic elasticity, considerable attention has been devoted to developing efficient algorithms for computing these quantities over the years. The mathematical complexity of this Green’s function has also posed an obstacle in the development of this numerical method to treat problems of 3D anisotropic thermoelasticity. This is because thermal effects manifest themselves as an additional domain integral in the integral equation;… More >