Home / Journals / CMES / Vol.78, No.3&4, 2011
Table of Content
  • Open Access

    ARTICLE

    Topological Optimization of Anisotropic Heat Conducting Devices using Bezier-Smoothed Boundary Representation

    C.T.M. Anflor1, R.J. Marczak2
    CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.3&4, pp. 151-168, 2011, DOI:10.3970/cmes.2011.078.151
    Abstract This paper aims to demonstrate the final result of an optimization process when a smooth technique is introduced between intermediary iterations of a topological optimization. In a topological optimization process is usual irregular boundary results as the final shape. This boundary irregularity occurs when the way of the material is removed is not very suitable. Avoiding an optimization post-processing procedure some techniques of smooth are implemented in the original optimization code. In order to attain a regular boundary a smoothness technique is employed, which is, Bezier curves. An algorithm was also developed to detect during the optimization process which curve… More >

  • Open Access

    ARTICLE

    Coupled Evolution of Damage and Fluid Flow in a Mandel-type Problem

    Eduardo T Lima Junior1, Wilson S Venturini2, Ahmed Benallal3
    CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.3&4, pp. 169-184, 2011, DOI:10.3970/cmes.2011.078.169
    Abstract Some considerations on the numerical analysis of brittle rocks are presented in this paper. The rock is taken as a poro-elastic domain, in full-saturated condition, based on the Biot's Theory. The solid matrix of this porous medium is considered to be susceptible to isotropic damage occurrence. An implicit boundary element method (BEM) formulation, based on time-independent fundamental solutions, is developed and implemented to couple the fluid flow and two-dimensional elastostatics problems. The integration over boundary elements is evaluated by using a numerical Gauss procedure. A semi-analytical scheme for the case of triangular domain cells is followed to carry out the… More >

  • Open Access

    ARTICLE

    Inverse Analysis of Solidification Problems Using the Mesh-Free Radial Point Interpolation Method

    A. Khosravifard1, M.R. Hematiyan1,2
    CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.3&4, pp. 185-208, 2011, DOI:10.3970/cmes.2011.078.185
    Abstract An inverse method for optimal control of the freezing front motion in the solidification of pure materials is presented. The inverse technique utilizes the idea of a pseudo heat source to account for the latent heat effects. The numerical formulation of this inverse method is based on a formerly introduced meshless technique. In this method, the flux and the velocity of the liquid-solid interface are treated as secondary variables and the liquid and solid domains are modeled simultaneously. Some numerical examples are provided to demonstrate the efficiency of the presented method. The effects of regularization and the number of nodes… More >

  • Open Access

    ARTICLE

    Application of the OMLS Interpolation to Evaluate Volume Integrals Arising in Static Elastoplastic Analysis via BEM

    K.I. Silva1, J.C.F. Telles2, F.C. Araújo3
    CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.3&4, pp. 209-224, 2011, DOI:10.3970/cmes.2011.078.209
    Abstract In this work the boundary element method is applied to solve 2D elastoplastic problems. In elastoplastic boundary element analysis, domain integrals have to be calculated to introduce the contribution of yielded zones. Traditionally, the use of internal integration cells have been adopted to evaluate such domain integrals. The present work, however, proposes an alternative cell free strategy based on the OMLS (Orthogonal Moving Least Squares) interpolation, typically adopted in meshless methods. In this approach the definition of points to compute the interpolated value of a function at a given location only depends on their relative distance, without need to define… More >

  • Open Access

    ARTICLE

    Numerical Design of Random Micro-Heterogeneous Materials with Functionally-Graded Effective Thermal Conductivities Using Genetic Algorithms and the Fast Boundary Element Method

    Marco Dondero1, Adrián P. Cisilino1,2, 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 >

  • Open Access

    ARTICLE

    A Constitutive Model for Porous Shape Memory Alloys Considering the Effect of Hydrostatic Stress

    Bingfei Liu1, Guansuo Dui1,2, Yuping Zhu3
    CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.3&4, pp. 247-276, 2011, DOI:10.3970/cmes.2011.078.247
    Abstract A constitutive model considering the effect hydrostatic stresses induced by porosity on the macroscopic behavior of porous Shape Memory Alloys (SMAs) is developed in this paper. First, a unit-cell model is adopted to establish the constitutive relations for the porous SMAs with SMA matrix and the porosity taken to be voids. Dilatational plasticity theory is then generalized for the SMA matrix. Based on an approximation of the velocity field and the upper bound theory, an explicit yield function for the porous SMA is derived from micromechanical considerations. Finally, an example for the uniaxial response under compression of a porous Ni-Ti… More >

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