D.S. Liu^1,2, Z.H. Fong¹, I.H. Lin¹, Z.W. Zhuang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.6, pp. 441-468, 2013, DOI:10.3970/cmes.2013.093.441

Abstract In this study, we proposed a novel numerical technique to simulate the transient moisture diffusion process and to apply it to heterogeneous composite resins. The method is based on a heterogeneous hybrid moisture element (HHME), with properties determined through an equivalent hybrid moisture capacitance/ conductance matrix that was calculated using the conventional finite element formulation in space discretization and the q-method in time discretization, with similar mass/stiffness properties and matrix condensing operations. A coupled HHME with finite element scheme was developed and implemented in the computer code by using the commercial software MATLAB to analyze the transient moisture diffusion process… More >

Marco Dondero¹, Adrián P. Cisilino^1,2, J. Pablo Tomba¹

CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.3&4, pp. 225-246, 2011, DOI:10.3970/cmes.2011.078.225

Abstract This paper introduces a numerical methodology for the design of random micro-heterogeneous materials with functionally graded effective thermal conductivities (ETC). The optimization is carried out using representative volume elements (RVEs), a parallel Genetic Algorithm (GA) as optimization method, and a Fast Multipole Boundary Element Method (FMBEM) for the evaluation of the cost function. The methodology is applied for the design of foam-like microstructures consisting of random distributions of circular insulated holes. The temperature field along a material sample is used as objective function, while the spatial distribution of the holes is the design variable. There are presented details of the… More >

D.S. Liu^1,2 , C.Y. Chen² , D.Y. Chiou³

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.2, pp. 179-192, 2005, DOI:10.3970/cmes.2005.009.179

Abstract A three-dimensional heterogeneous infinite element method (HIEM) for modeling inclusions with interphases in composite materials is presented. This special element is formulated based on the conventional finite element method (FEM) using the similarity stiffness property and matrix condensation operations. An HIE-FE coupling scheme is also developed and implemented using the commercial software ABAQUS to conduct the elastostatic analysis. The proposed approach was validated first to study heterogeneous material containing one spherical inclusion. The displacement and stress variations around the inclusion vicinity are verified against conventional FEM. The proposed approach was next applied to analyze the effective modulus of single-particle and… More >

Paul R. Dawson¹, Donald E. Boyce², Ronald Rogge³

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.2, pp. 123-142, 2005, DOI:10.3970/cmes.2005.010.123

Abstract Computational mechanics provides a powerful environment for modeling the evolution of material structure during deformation processes and for associating that evolution with changes to the mechanical properties. In this paper, we illustrate a two-scale formulation that links the mechanical loading applied at the scale of a component (the continuum scale) to the responses of the material at the scale of the crystals that comprise it (the crystal scale). Employing the capabilities offered by computational mechanics, we can better understand how heterogeneity of deformation arising at both the continuum and crystal scales influences the behaviors observed experimentally. Such an understanding is… More >

V. Carvelli², G. Maier², A. Taliercio²

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.2, pp. 19-30, 2000, DOI:10.3970/cmes.2000.001.179

Abstract Homogenization of periodic fiber-reinforced ductile composite materials is performed as for the material strength, i.e. the carrying capacity with respect to macroscopic (average) stresses. Rigid-plastic limit analysis is formulated by the kinematic theorem applied to the representative volume with periodicity boundary conditions and von Mises yield criterion. The iterative procedure adopted for the numerical solution of the minimization problem is comparatively discussed on the basis of applications to various ductile heterogeneous media. More >

K. Choukairy¹, R. Bennacer²

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.2, pp. 155-172, 2012, DOI:10.3970/fdmp.2012.008.155

Abstract This study carries the natural thermosolutal convection induced in heterogeneous porous media. The configuration considered is cartesian. The horizontal and vertical walls are submitted to different mass and heat transfer. The equations which govern this type of flow are solved numerically by using the finite volume method. The flow is considered two-dimensional and laminar. The model of Darcy and the approximation of the Boussinesq are taken into account. The parameters which control the problem are the thermal Darcy-Rayleigh number, Rt, the buoyancy ratio, N, the Lewis number, Le, the aspect ratio of the enclosure, A and the local permeability ratio,… More >

Evgeny V. Votyakov¹, Egbert A. Zienicke¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.2, pp. 97-114, 2007, DOI:10.3970/fdmp.2007.003.097

Abstract We simulated numerically the laminar flow in the geometry and the magnetic field of the experimental channel used in [Andreev, Kolesnikov, and Thess (2006)]. This provides detailed information about the electric potential distribution for the laminar regime (numerical simulation) and in the turbulent regime as well (experiment). As follows from comparison of simulated and experimental results, the flow under the magnet is determined by the interaction parameter N = Ha² / Re representing the ratio between magnetic force, determined by the Hartmann number Ha, and inertial force, determined by the Reynolds number Re. We compared two variants: (i)(Re,N)=(2000,18.6) (experiment), (400,20.25)… More >

Zhenhan Yao¹, Lingfei Gao¹

CMC-Computers, Materials & Continua, Vol.9, No.1, pp. 1-24, 2009, DOI:10.3970/cmc.2009.009.001

Abstract To improve the effectiveness of the lattice model for simulating the failure processes of heterogeneous brittle materials, each lattice element is refined as a subdomain with homogenous material, and is modeled by the boundary element method in this paper. For simplicity, each subdomain is modeled with constant boundary elements. To enhance the efficiency, a row of sub-domains is formed, and then a chain structure of such row-subdomain is constructed. The row-equation systems are solved one by one, and then back substituted, to obtain the final solution. Such a chain subdomain approach of the boundary element method not only reduces the… More >

L.M. Xu¹, H. Fan^2,3, X M Xie³, C. Li³

CMC-Computers, Materials & Continua, Vol.7, No.3, pp. 119-128, 2008, DOI:10.3970/cmc.2008.007.119

Abstract In the present study we performed finite element simulation for bi-continuous heterogeneous solids via a random distribution of materials to predict effective elastic properties. With a random distributing scheme, a statistical analysis via finite element becomes feasible for the multi-phase heterogeneous solids. Using a two-phase bi-continuous material as example, the numerical prediction of the effective properties is obtained in terms of a mean value and standard deviation with a sample size of 30 for each of given volume fraction. The finite element simulation results fall within the analytical bounds proposed by Hashin and Shtrikman (1963) based on the principle of… More >

Changming Zhao^1,2,*, Tiejun Wang², Alan Yang³

CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 423-437, 2019, DOI:10.32604/cmc.2019.07501

Abstract In the paper, we investigate the heterogeneous resource allocation scheme for virtual machines with slicing technology in the 5G/B5G edge computing environment. In general, the different slices for different task scenarios exist in the same edge layer synchronously. A lot of researches reveal that the virtual machines of different slices indicate strong heterogeneity with different reserved resource granularity. In the condition, the allocation process is a NP hard problem and difficult for the actual demand of the tasks in the strongly heterogeneous environment. Based on the slicing and container concept, we propose the resource allocation scheme named Two-Dimension allocation and… More >