Han-Taw Chen¹, Li-Shie Liu¹, Shin-Ku Lee¹

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.2, pp. 155-178, 2010, DOI:10.3970/cmes.2010.065.155

Abstract The finite difference method in conjunction with the least-squares scheme and experimental measured temperatures is proposed to solve a two-dimensional steady-state inverse heat conduction problem in order to predict the natural-convection heat transfer coefficient under the isothermal situation h^−iso from a three fin array mounted on a horizontal plate and fin efficiency η_f for various values of the fin spacing and fin height. The measured fin temperatures and ambient temperature are obtained from the present experimental apparatus conducted in a small wind tunnel. The heat transfer coefficient on a fin is non-uniform for the present problem, and its functional… More >

J.H. Tian^1,2, X. Han², S.Y. Long², G.Y. Sun², Y. Cao¹, G.Q. Xie³

CMES-Computer Modeling in Engineering & Sciences, Vol.63, No.2, pp. 101-116, 2010, DOI:10.3970/cmes.2010.063.101

Abstract A transient heat conduction analysis of the functionally graded material (FGM) plates has been investigated based on the hybrid numerical method (HNM). HNM combines the layer element method with the method of Fourier transforms and proves to be efficient and reliable. The FGM plates are infinite large and the material properties vary continuously through thickness. The transient heat source acted on the FGM plates. The temperature distribution of the FGM plates is obtained in different time and different position. Some useful results for transient heat conduction are shown in figures. Applications of HNM to transient heat conduction are firstly presented… More >

Claire Heaney^1,2, Charles Augarde², Andrew Deeks²

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.2, pp. 153-178, 2010, DOI:10.3970/cmes.2010.056.153

Abstract Meshless methods continue to generate strong interest as alternatives to conventional finite element methods. One major area of application as yet relatively unexplored with meshless methods is elasto-plasticity. In this paper we extend a novel numerical method, based on the Meshless Local Petrov-Galerkin (MLPG) method, to the modelling of elasto-plastic materials. The extended method is particularly suitable for problems in geomechanics, as it permits inclusion of infinite boundaries, and is demonstrated here on footing problems. The current usage of meshless methods for problems involving plasticity is reviewed and guidance is provided in the choice of various modelling parameters. More >

Yu Miao¹, Qiao Wang¹, Bihai Liao^1,2, Junjie Zheng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.53, No.1, pp. 1-22, 2009, DOI:10.3970/cmes.2009.053.001

Abstract As a truly meshless method, the Hybrid Boundary Node method (Hybrid BNM) does not require a `boundary element mesh', either for the purpose of interpolation of the solution variables or for the integration of `energy'. This paper presents a further development of the Hybrid BNM to the 2D elastodynamics. Based on the radial basis function (RBF) and the Hybrid BNM, it presents an inherently meshless, boundary-only technique, which named dual hybrid boundary node method (DHBNM), for solving 2D elastodynamics. In this study, the RBFs are employed to approximate the inhomogeneous terms via dual reciprocity method (DRM), while the general solution… More >

F. Yan^1,2, Y. Miao^2,3, Q. N. Yang²

CMES-Computer Modeling in Engineering & Sciences, Vol.46, No.1, pp. 21-50, 2009, DOI:10.3970/cmes.2009.046.021

Abstract A novel boundary type meshless method called Quasilinear Hybrid Boundary Node Method (QHBNM), which combines quasilinearization method, dual reciprocity method (DRM) and hybrid boundary node method (HBNM), is developed to solving a class of nonlinear problems. The nonlinear term of the governing equation is linearized by the generated quasilinearization method, in which the solution of the linearized equation can exactly converge to the solution of original equation at a very wide range initial value, and the convergence rate is quadratic. Then dual hybrid boundary node method is applied to solving the linearized equation, in which DRM is introduced into HBNM… More >

Y.-M. Guo¹

CMES-Computer Modeling in Engineering & Sciences, Vol.41, No.3, pp. 177-194, 2009, DOI:10.3970/cmes.2009.041.177

Abstract In this paper, for analyses of the rigid-plastic metal forming problems, a hybrid PCM/FEM is developed. By introducing a boundary layer of finite element in boundary domain of workpiece, unsatisfactory issue of the positivity conditions of boundary points can be avoided, and the complicated boundary conditions can be easily imposed with the boundary layer of finite element. A plane strain upsetting process is analyzed by using the hybrid PCM/FEM. More >

Cha’o-Kuang Chen^1,2, Hsin-Yi Lai¹, Chin-Chia Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.40, No.2, pp. 155-174, 2009, DOI:10.3970/cmes.2009.040.155

Abstract Electrostatically-actuated micro circular plates are used in many micro-electro-mechanical systems (MEMS) devices nowadays such as micro pumps and optical switches. However, the dynamic behavior of these circular plates is not easily analyzed using traditional analytic methods due to the complexity of the interactions between the electrostatic coupling effects. Accordingly, this study develops an efficient computational scheme in which the nonlinear governing equation of the coupled electrostatic force acting on the micro circular plate is solved using a hybrid differential transformation / finite difference approximation method. In deriving the dynamic equation of motion of the micro plate, explicit account is taken… More >

N.Kringos¹, A.Scarpas¹, A.P.S. Selvadurai²

CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.3, pp. 147-160, 2008, DOI:10.3970/cmes.2008.028.147

Abstract This paper presents a numerical approach for the modeling of water flow induced mastic erosion from a permeable asphalt mix and is part of an ongoing effort to model moisture-induced damage in asphalt mixes. Due to the complex composite structure of asphalt mixtures, moisture can infiltrate in various ways into the components and have an adverse effect on its mechanical performance. Depending on the gradation of the asphalt aggregates and the mixing procedure, asphalt structures with a variable permeability may result. Open-graded asphalt mixes are designed with a high interconnected air void content to serve as a drainage layer on… More >

S.Y. Wang^1,2, K.M. Lim^2,3, B.C. Khoo^2,3, M.Y. Wang⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.1, pp. 21-50, 2008, DOI:10.3970/cmes.2008.024.021

Abstract In topology optimization, filtering techniques have become quite popular in practice. In this paper, an accurate and efficient hybrid sensitivity filtering approach based on the traditional and bilateral sensitivity filtering approaches is proposed. In the present hybrid approach, the traditional sensitivity filter is applied to a sub-domain where numerical instabilities are likely to occur to overcome the numerical instabilites robustly. Filtering on mesh-independent holes identified by an image-processing-based technique is prohibited to reduce the computational cost. The bilateral approach is employed for the corresponding nearest neighboring elements of the mesh-independent holes to drive the 0-1 convergence of their boundaries. As… More >

E.J. Sellountos¹, A. Sequeira¹

CMES-Computer Modeling in Engineering & Sciences, Vol.23, No.2, pp. 127-148, 2008, DOI:10.3970/cmes.2008.023.127

Abstract In this work a hybrid velocity-vorticity scheme for the solution of the 2D Navier-Stokes equations is presented. The multi-region Local Boundary Integral Equation (LBIE) combined with Radial Basis Functions (RBF) interpolation is used for the solution of the kinematics and the multi-region BEM for the solution of the transport kinetics. The final system of equations is in band form for both methods. The issue of RBF discontinuities is resolved by constructing the RBF matrix locally in every region. The kinematics integral equation is used in three different forms, for coupling the velocity field on the boundary, on interior points and… More >