Zhiqiang Yang¹, Yufeng Nie², Yatao Wu², Zihao Yang², Yi Sun¹

CMC-Computers, Materials & Continua, Vol.43, No.1, pp. 21-48, 2014, DOI:10.3970/cmc.2014.043.021

Abstract This paper develops a novel statistical second-order two-scale (SSOTS) method to predict the heat transfer performances of three-dimensional (3D) porous materials with random distribution. Firstly, the mesoscopic configuration for the structure with random distribution is briefly characterized Secondly, the SSOTS formulas for calculating effective thermal conductivity parameters, temperature field and heat flux densities are derived by means of construction way. Then, the algorithm procedure based on the SSOTS method is described in details. Finally, numerical results for porous materials with varying probability distribution models are calculated by SSOTS algorithm, and compared with the data by finite element method (FEM) in… More >

Y. T. Wu¹, J. Z. Cui², Y. F. Nie³, Y. Zhang³

CMC-Computers, Materials & Continua, Vol.42, No.3, pp. 205-226, 2014, DOI:10.3970/cmc.2014.042.205

Abstract Core–shell particle–filled PA6/EPDM–g–MA/HDPE ternary blend has excellent mechanical properties. In this paper, effective elastic properties and tensile yield strength of the ternary blend are predicted by the second–order two– scale method, to investigate the relationship between morphology and mechanical properties. The method and the limit analysis for predicting mechanical properties of random heterogeneous materials are briefly introduced. Realistic morphology of the ternary blend including both core–shell particles and pure particles is simulated, and finite element mesh is generated. The unified strength theory is embedded in the method for the convenience of selecting a suitable yield criterion. The effective elastic moduli… More >

Chein-Shan Liu¹

CMC-Computers, Materials & Continua, Vol.39, No.2, pp. 153-178, 2014, DOI:10.3970/cmc.2014.039.153

Abstract For the numerical solution of an ill-posed positive linear system we combine the methods from invariant manifold theory and sliding mode control theory, developing an affine nonlinear dynamical system with a positive control force and with the residual vector as being a gain vector. This system is proven asymptotically stable to the zero residual vector by using an argument from the Lyapunov stability theory. We find that the system fast tends to the sliding surface and then moves with a sliding mode, such that the resultant sliding mode control algorithm (SMCA) is robust against large noise and stable to find… More >

M. Marin¹, S. R. Mahmoud^2,3, K. S. Al-Basyouni⁴

CMC-Computers, Materials & Continua, Vol.37, No.1, pp. 23-37, 2013, DOI:10.3970/cmc.2013.037.023

Abstract Taking advantage of the flexibility of Lagrange’s identity, we prove the uniqueness theorem and some continuous dependence theorems without recourse to any energy conservation law, or to any boundedness assumptions on the constitutive coefficients. Also, we avoid the use of positive definiteness assumptions on the constitutive coefficients, even if these results are related to the difficult mixed problem in elasticity of micromorphic bodies. More >

E. Ferretti¹

CMC-Computers, Materials & Continua, Vol.36, No.3, pp. 293-322, 2013, DOI:10.3970/cmc.2013.036.293

Abstract The Cell Method is applied in order to model the debonding mechanism in ceramic floor tiles subjected to positive thermal variation. The causes of thermal debonding, very usual in radiant heat floors, have not been fully clarified at the moment. There exist only a few simplified analytical approaches that assimilate this problem to an eccentric tile compression, but these approaches introduce axial forces that, in reality, do not exist. In our work we have abandoned the simplified closed form solution in favor of a numerical solution, which models the interaction between tiles and sub-base more realistically, when the positive thermal… More >

K. Mramor¹, R. Vertnik^2,3, B. Šarler^1,3,4,5

CMC-Computers, Materials & Continua, Vol.36, No.1, pp. 1-21, 2013, DOI:10.3970/cmc.2013.036.001

Abstract This paper explores the application of Local Radial Basis Function Collocation Method (LRBFCM) [Šarler and Vertnik (2006)] for solution of Newtonian incompressible 2D fluid flow for a lid driven cavity problem [Ghia, Ghia, and Shin (1982)] in primitive variables. The involved velocity and pressure fields are represented on overlapping five-noded sub-domains through collocation by using Radial Basis Functions (RBF). The required first and second derivatives of the fields are calculated from the respective derivatives of the RBF’s. The momentum equation is solved through explicit time stepping. The method is alternatively structured with multiquadrics and inverse multiquadrics RBF’s. In addition, two… More >

M. Chatiri¹, A. Matzenmiller²

CMC-Computers, Materials & Continua, Vol.35, No.3, pp. 255-283, 2013, DOI:10.3970/cmc.2013.035.255

Abstract This article presents a three dimensional constitutive model for anisotropic damage to describe the elastic-brittle behavior of unidirectional fibrereinforced laminated composites. The primary objective of the article focuses on the three dimensional relationship between damage of the material and the effective elastic properties for the purpose of stress analysis of composite structures, in extension to the two dimensional model in Matzenmiller, Lubliner and Taylor (1995). A homogenized continuum is adopted for the constitutive theory of anisotropic damage and elasticity. Damage initiation criteria are based on Puck failure criterion for first ply failure and progressive micro crack propagation is based on… More >

Chih-Wen Chang^1,2, Chein-Shan Liu³

CMC-Computers, Materials & Continua, Vol.34, No.2, pp. 143-175, 2013, DOI:10.3970/cmc.2013.034.143

Abstract The nonlinear Poisson problems in heat diffusion governed by elliptic type partial differential equations are solved by a modified globally optimal iterative algorithm (MGOIA). The MGOIA is a purely iterative method for searching the solution vector x without using the invert of the Jacobian matrix D. Moreover, we reveal the weighting parameter αc in the best descent vector w = αcE + DTE and derive the convergence rate and find a criterion of the parameter γ. When utilizing αc and γ, we can further accelerate the convergence speed several times. Several numerical experiments are carefully discussed and validated the proposed… More >

Cheng-Te Chi¹, Ming-Hsiao Lee², Wen-Hwa Chen^1,3

CMC-Computers, Materials & Continua, Vol.24, No.3, pp. 239-256, 2011, DOI:10.3970/cmc.2011.024.239

Abstract A novel three-dimensional adaptive element-free Galerkin method (EFGM) based on a uniform background grid is proposed to cope with the problems with extremely large deformation. On the basis of this uniform background grid, an interior adaptive strategy through an error estimation within the analysis domain is developed. By this interior adaptive scheme, additional adaptive nodes are inserted in those regions where the solution accuracy needs to be improved. As opposed to the fixed uniform background grid, these inserted nodes can move along with deformation to describe the particular local deformation of the structure. In addition, a triangular surface technique is… More >

Chih-Wen Chang¹

CMC-Computers, Materials & Continua, Vol.24, No.3, pp. 209-238, 2011, DOI:10.3970/cmc.2011.024.209

Abstract In this study, we employ a semi-analytical scheme to resolve the three-dimensional backward heat conduction problem (BHCP) by utilizing a quasi-bound -ary concept. First, the Fourier series expansion method is used to estimate the temperature field u(x, y, z, t) at any time t < T. Second, we ponder a direct regularization by adding an extra term a(x, y, z, 0) to transform a second-kind Fredholm integral equation for u(x, y, z, 0). The termwise separable property of the kernel function allows us to acquire a closed-form regularized solution. In addition, a tactic to determine the regularization parameter is recommended.… More >