Yui-Chuin Shiah^{1, *}, Sheng-Chi Huang¹, M. R. Hematiyan²

CMC-Computers, Materials & Continua, Vol.64, No.2, pp. 701-727, 2020, DOI:10.32604/cmc.2020.010417 - 10 June 2020

Abstract In engineering practice, analysis of interfacial thermal stresses in composites is a crucial task for assuring structural integrity when sever environmental temperature changes under operations. In this article, the directly transformed boundary integrals presented previously for treating generally anisotropic thermoelasticity in two-dimension are fully regularized by a semi-analytical approach for modeling thin multi-layers of anisotropic/isotropic composites, subjected to general thermal loads with boundary conditions prescribed. In this process, an additional difficulty, not reported in the literature, arises due to rapid fluctuation of an integrand in the directly transformed boundary integral equation. In conventional analysis, thin… More >

Yue Jia¹, Chun Li^{1, *}, Jinwu Jiang², Ning Wei³, Yang Chen⁴, Yongjie Jessica Zhang⁵

CMC-Computers, Materials & Continua, Vol.63, No.2, pp. 813-823, 2020, DOI:10.32604/cmc.2020.07801 - 01 May 2020

Abstract The present work carries out molecular dynamics simulations to compute the thermal conductivity of the borophene nanoribbon and the borophene nanotube using the Muller-Plathe approach. We investigate the thermal conductivity of the armchair and zigzag borophenes, and show the strong anisotropic thermal conductivity property of borophene. We compare results of the borophene nanoribbon and the borophene nanotube, and find the thermal conductivity of the borophene is orientation dependent. The thermal conductivity of the borophene does not vary as changing the width of the borophene nanoribbon and the perimeter of the borophene nanotube. In addition, the More >

Behrouz Karami¹, Maziar Janghorban¹, Timon Rabczuk^{2, *}

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 607-629, 2020, DOI:10.32604/cmc.2020.08032

Abstract This study investigates the forced vibration of functionally graded hexagonal nano-size plates for the first time. A quasi-three-dimensional (3D) plate theory including stretching effect is used to model the anisotropic plate as a continuum one where smallscale effects are considered based on nonlocal strain gradient theory. Also, the plate is assumed on a Pasternak foundation in which normal and transverse shear loads are taken into account. The governing equations of motion are obtained via the Hamiltonian principles which are solved using analytical based methods by means of Navier’s approximation. The influences of the exponential factor, More >

Yunfa Zhang¹, Xiaozhou Xia^{1, *}, Zhenjie Wu¹, Qing Zhang¹

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 413-442, 2020, DOI:10.32604/cmc.2020.04660

Abstract Considering the fact that the initial defects, like the imperfect interfacial transition zones (ITZ) and the micro voids in mortar matrix, weaken the mechanical properties of concrete, this study develops corresponding constitutive models for ITZ and matrix, and simulates the concrete failure with finite element methods. Specifically, an elastic-damage traction-separation model for ITZ is constructed, and an anisotropic plastic-damage model distinguishing the strength-difference under tension and compression for mortar matrix is proposed as well. In this anisotropic plastic-damage model, the weakening effect of micro voids is reflected by introducing initial isotropic damage, the distinct characteristic More >

Takeo Matsumoto^1,*, Chizuru Hirooka¹, Yong Fan¹, Junfeng Wang¹, Naoki Mori¹, Eijiro Maeda¹

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 81-81, 2019, DOI:10.32604/mcb.2019.07102

Abstract Aortic wall thickens in response to hypertension. Many studies reported that the wall thickening occurs to maintain the wall stress in the circumferential direction at a constant level. In case of the longitudinal direction, however, there are few studies suggesting the constancy of the stress. Such anisotropic response may be attributable to the circumferential alignment of the smooth muscle cells (SMCs) in the wall [1]. However, to the authors’ knowledge, there are no study discussing the underlying mechanism of the anisotropic response. It has been reported that mechanical deformation of the nuclei causes transcription upregulation… More >

Jing Wang^1,*, Xiaohe Qiu¹, Yuanfei Tu¹

CMC-Computers, Materials & Continua, Vol.60, No.1, pp. 227-244, 2019, DOI:10.32604/cmc.2019.05281

Abstract The MDS-MAP (multidimensional scaling-MAP) localization algorithm utilize almost merely connectivity information, and therefore it is easy to implement in practice of wireless sensor networks (WSNs). Anisotropic networks with energy hole, however, has blind communication spots that cause loss of information in the merging phase of MDSMAP. To enhance the positioning accuracy, the authors propose an MDS-MAP (CH) algorithm which can improve the clustering and merging strategy. In order to balance the effect of energy consumption and the network topology stabilization, we present a weighted clustering scheme, which considers the residual energy, the degree of connectivity More >

Mohamed Ben Gharsallah^a, Issam Ben Mhammed^b, Ezzedine Ben Braiek^a

Intelligent Automation & Soft Computing, Vol.24, No.2, pp. 231-240, 2018, DOI:10.1080/10798587.2016.1262457

Abstract In radiography imaging, contrast, sharpness and noise there are three fundamental factors that determine the image quality. Removing noise while preserving and sharpening image contours is a complicated task particularly for images with low contrast like radiography. This paper proposes a new anisotropic diffusion method for radiography image enhancement. The proposed method is based on the integration of geometric parameters derived from the local pixel intensity distribution in a nonlinear diffusion formulation that can concurrently perform the smoothing and the sharpening operations. The main novelty of the proposed anisotropic diffusion model is the ability to More >

Z. Neffah¹, H. Kahalerras^{1, *}, B. Fersadou¹

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.1, pp. 39-56, 2018, DOI:10.3970/fdmp.2018.014.039

Abstract A numerical study of heat and mass transfer in a non-Newtonian fluid in a parallel-plate channel partly filled with an anisotropic porous medium and subjected to an exothermic chemical reaction on its walls has been conducted. The flow field in the porous region has been modeled by the modified Brinkman-Forchheimer extended Darcy model for power-law fluids and a finite volume method has been used to solve the governing equations. The influence played by a variation of the anisotropic ratio on thermal conductivity, power-law index, Darcy number, and chemical reaction characteristics has been examined. We show More >

Marwa Abida^1,2, Jamel Mars^3,*, Florian Gehring¹, Alexandre Vivet¹, Fakhreddine Dammak³

Journal of Renewable Materials, Vol.6, No.5, pp. 464-476, 2018, DOI:10.32604/JRM.2018.01897

Abstract Based on experimental test results, flax fiber reinforced polymer composites are characterized by nonlinear visco-elastoplastic behavior. The aim of this work is to model the quasi-unidirectional flax fiber reinforced composite behavior through a three dimensional formulation with orthotropic elasticity and orthotropic plasticity using Hill criterion. The isotropic hardening and Johnson Cook parameters are identified from unidirectional tensile tests at different strain rates. The adjustment of Hill’s yield criterion is developed based on yield stresses obtained in tensile tests at different directions. The numerical integration of the constitutive equations is implemented in a user-defined material, UMAT More >

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 >