Che-Wun Hong^1,2, Wei-Hui Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.3, pp. 211-228, 2011, DOI:10.3970/cmes.2011.072.211

Abstract This paper intends to use semiconductor quantum dots (cadmium sulphide- CdS) and/or biological pigments (chlorophyll-a derivatives) to replace those expensive ruthenium (Ru) dyes in photoelectrochemical solar cells. Based on the computational quantum chemistry, the molecular structures of (CdS)_n (n=1 ~ 22) clusters and chlorophyll-a derivatives (chlorin-H₃⁺ and chlorin-H₁₇⁺) are configured and optimized. Density functional theory (DFT) of the first principles calculations, which chose B3LYP (Becke 3-parameter Lee-Yang-Parr) and PBE (Perdew-Burke- Ernzerhof) exchange correlation functionals, is employed. Photoelectric properties, such as: molecular orbital, density of state (DOS), highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and resultant band gaps… More >

D. Mirzaei¹, M. Dehghan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.3, pp. 185-210, 2011, DOI:10.3970/cmes.2011.072.185

Abstract The meshless local Petrov-Galerkin (MLPG) method with an efficient technique to deal with the time variable are used to solve the heat conduction problem in this paper. The MLPG is a meshless method which is (mostly) based on the moving least squares (MLS) scheme to approximate the trial space. In this paper the MLS is used for approximation in both time and space domains, and we avoid using the time difference discretization or Laplace transform method to overcome the time variable. The technique is applied for continuously nonhomogeneous functionally graded materials (FGM) in a finite strip and a hallow cylinder.… More >

F. Guarracino ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.3, pp. 167-184, 2011, DOI:10.3970/cmes.2011.072.167

Abstract The design of many engineering problems requires accurate test results and interpretation in order to evaluate the carrying capacity of circular cylindrical shells subjected to various loads including bending. Apparently anomalous values of axial tensile and compressive strains from recent test results have been lately investigated and explained using Finite Element modeling. As a complement to numerical analyses, in the present paper a simple analytical formula for the estimation of the effects of local conditions in tubes testing and design is provided on the basis of an extended Ritz's approach and of the general linear theory of shells. The findings… More >

Duning Li¹, Yufeng Nie^1,2, Xuemei Zhou¹, Li Cai¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 149-166, 2011, DOI:10.3970/cmes.2011.072.149

Abstract In this study, the efficient discrete model including the resin infusion and the fiber compaction is developed to simulate the RFI (resin film infusion) process. The non-linear governing equations are derived by the Darcy's law, the Terzaghi's law and the continuity equations. The finite element method and the finite difference method are used to discretize the proposed equations, and the VOF method is used to track the filling front. Compared with the analytical results of Park, our numerical results agree well with them. Furthermore, we analyze the RFI process of BMI/G0814, and simulate the resin pressure, the fiber volume fraction… More >

H. T. Wang^1,2, Z. H. Yao³

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 115-148, 2011, DOI:10.3970/cmes.2011.072.115

Abstract A fast boundary element solver for the analysis of three-dimensional general crack problems is presented. In order to effectively model the embedded or edge cracked structures a dual boundary integral equation (BIE) formulation is used. By implementing the fast multipole method (FMM) to the discretized BIE, structures containing a large number of three-dimensional cracks can be readily simulated on one personal computer. In the FMM framework, a multipole expansion formulation is derived for the hyper-singular integral in order that the multipole moments of the dual BIEs containing the weakly-, strongly- and hyper-singular kernels are collected and translated with a unified… More >

Quan Zheng², Jing Wang², Jing-ya Li²

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 103-114, 2011, DOI:10.3970/cmes.2011.072.103

Abstract This paper investigates the coupling method of the finite element and the natural boundary element using an elliptic artificial boundary for solving exterior anisotropic problems, and obtains a new error estimate that depends on the mesh size, the location of the elliptic artificial boundary, the number of terms after truncating from the infinite series in the integral. Numerical examples are presented to demonstrate the effectiveness and the properties of this method. More >

N. Liu,¹,W. Gao ¹, C.M. Song¹, N. Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 79-102, 2011, DOI:10.3970/cmes.2011.072.079

Abstract This paper presents the probabilistic dynamic analysis of vehicle-bridge interaction systems. The bridge's and vehicle's parameters are considered as random variables as well as the road surface roughness is modeled as random process. A two-degree-of-freedom spring-mass system is used to represent a moving vehicle and the bridge is modeled as an Euler-Bernoulli beam. From the equation of motion for the vehicle-bridge coupling system, the expressions for mean value and standard deviation of bridge response are developed by using the random variable's functional moment method. The effects of the individual system parameters and the road surface roughness on the bridge response… More >

Chun Yang^1,2, Dalin Tang², Satya Atluri³

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.1, pp. 53-78, 2011, DOI:10.3970/cmes.2011.072.053

Abstract Previously, we introduced a computational procedure based on three-dimensional meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Structure-only models were used in our previous report. In this paper, fluid-stricture interaction (FSI) was added to improve on prediction accuracy. One participating patient was scanned three times (T1, T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Blood flow was assumed to laminar, Newtonian, viscous and incompressible. The Navier-Stokes equations with arbitrary Lagrangian-Eulerian (ALE) formulation were used as the governing… More >

Jui-Hsun Ni, Cheng-Chi Chang, Yue-Tzu Yang, Cha’o-Kung Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.1, pp. 37-52, 2011, DOI:10.3970/cmes.2011.072.037

Abstract The hybrid method, which combines differential transformation and finite difference approximation techniques, is utilized to solve hyperbolic-type heat conduction (bio-heat) problems in one dimension. To capture the thermal behavior in a living tissue subjected to constant or exponential surface heating with the thermal wave model of bio-heat transfer, the relaxation time and the heat wave, which propagates in a direction perpendicular to the skin surface, are considered. The results show that the hybrid method can be used to solve hyperbolic heat conduction problems accurately. More >

Shueei-Muh Lin ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.1, pp. 17-36, 2011, DOI:10.3970/cmes.2011.072.017

Abstract In this study, examine the in-plane vibration of a robot arm picking and placing a mass along arbitrary curved tracking. This mathematical model is established. It is a moving mass problem. Due to the effect of movement along arbitrary curved tracking, the corresponding differential equation is nonlinear with the time-dependent coefficients and non-homogenous boundary conditions. So far, a few literatures devoted to investigate this system due to its complexity. The solution method procedure for this system is presented. It integrates several methods as the transform of variable, the subsection method, the mode superposition method, and the Green function method. Meanwhile,… More >