Zhen Yang¹, Xingsheng Gu², Xiaoyi Liang^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.74, No.3&4, pp. 161-182, 2011, DOI:10.3970/cmes.2011.074.161

Abstract Mesoporous carbons are synthesized by organic-organic self-assembly of triblock copolymer F127 and a new type of carbon precursor as resorcinol-furfural oligomers. Some factors will impact the mesoporous carbons pore structure and properties were studied. The main factors, such as the ratio of triblock copolymer F127 and oligomers, degree of polymerizstry of resorcinol-furfural oligomers, the ratio of resorcinol-furfural oligomers - F/R, and their mutual relations were identified. Aimed at balancing the complex characteristic of mesoporous structure and adsorption properties, a classification and optimization model based on support vector machine is developed. The optimal operation conditions of More >

T. Nakamura¹, R. Kobyashi¹, S. Ogata¹

CMES-Computer Modeling in Engineering & Sciences, Vol.73, No.4, pp. 357-386, 2011, DOI:10.3970/cmes.2011.073.357

Abstract The coarse-grained particle (CGP) method has been proposed to coarse-grain a crystalline system of atoms to meso-scale. In the method, virtual particles are distributed in the system, and the inter-particle interaction is calculated through the constrained statistical ensemble average of the atomic Hamiltonian at a given temperature. For simplicity, however, the harmonic approximation has been used for the inter-atomic interaction and hence anharmonicity at finite temperatures has been ignored. We improve the former CGP method to incorporate the anharmonicity of atomic system at finite temperatures into the inter-particle interaction. Also the divide-and-conquer strategy is applied 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… More >

Hua Zou¹, Hua Li^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.67, No.1, pp. 55-78, 2010, DOI:10.3970/cmes.2010.067.055

Abstract A novel meshless technique termed the Random Integral Quadrature (RIQ) method is developed in this paper for solving the generalized integral equations. By the RIQ method, the governing equations in the integral form are discretized directly with the field nodes distributed randomly or uniformly, which is achieved by discretizing the integral governing equations with the generalized integral quadrature (GIQ) technique over a set of background virtual nodes, and then interpolating the function values at the virtual nodes over a set of field nodes with Local Kriging method, where the field nodes are distributed either randomly… More >

Sunilkumar N¹, D Roy^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.66, No.3, pp. 249-284, 2010, DOI:10.3970/cmes.2010.066.249

Abstract We propose a family of 3D versions of a smooth finite element method (Sunilkumar and Roy 2010), wherein the globally smooth shape functions are derivable through the condition of polynomial reproduction with the tetrahedral B-splines (DMS-splines) or tensor-product forms of triangular B-splines and 1D NURBS bases acting as the kernel functions. While the domain decomposition is accomplished through tetrahedral or triangular prism elements, an additional requirement here is an appropriate generation of knotclouds around the element vertices or corners. The possibility of sensitive dependence of numerical solutions to the placements of knotclouds is largely arrested… More >

Xue-Qian Fang¹, Jin-Xi Liu¹, Ming-Zhang Chen¹, Li-Yong Fu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.66, No.2, pp. 101-116, 2010, DOI:10.3970/cmes.2010.066.101

Abstract In the authors' previous work (Zhang et al., 2010), the dynamic stress resulting from two cavities in exponential functional graded materials subjected to non-homogeneous shear waves has been studied. In this paper, the wave function expansion method is further developed to the case of two cylindrical inclusions embedded in functional graded materials, and the incident angle is also considered. The multiple scattering and refraction of non-homogeneous shear waves around the two inclusions are described accurately. The dynamic stress concentration factors around the two inclusions are presented analytically and numerically. The multiple effects of geometrical and More >

B.I. Yun¹, W.T. Ang^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.3, pp. 217-244, 2010, DOI:10.3970/cmes.2010.065.217

Abstract A dual-reciprocity boundary element method is proposed for simulating numerically axisymmetric dual-phase-lag heat conduction in nonhomogeneous thermally isotropic media. The properties of the media, such as thermal conductivity and specific heat, are assumed to vary continuously in space. To check its validity and assess its accuracy, the proposed method is first applied to solve some specific test problems with known solutions. It is then used to simulate the axisymmetric dual-phase-lag heat conduction in a particular nonhomogeneous medium subject to a concentrated surface heating. The effects of the dual phase lags and the spatial variations of More >

D. Kakogiannis¹, D. Van Hemelrijck¹, J. Wastiels¹, S. Palanivelu², W. Van Paepegem², J. Vantomme³, A. Kotzakolios⁴, V. Kostopoulos⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.1, pp. 75-94, 2010, DOI:10.3970/cmes.2010.065.075

Abstract In the present study the estimation of the blast wave by two types of finite element methods is investigated: Eulerian multi-material modeling and pure Lagrangian. The main goal is to compare and study their ability to predict the clearing effect during blast. Element shape and improvements on the codes are also considered. For the Lagrangian finite element models the load is applied by using an empirical method, deriving from databases, for the time-spatial distribution of the pressure profiles. In the ideal case of the above method the blast load is applied as an equivalent triangular… More >

Veturia Chiroiu, Ligia Munteanu¹, Adrian Toader²

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.1, pp. 1-26, 2010, DOI:10.3970/cmes.2010.065.001

Abstract The best methods of the genetic algorithms (GA) are obtained in order to optimize the shape of a thin elastic rod subjected to spatial bending and torsion. The optimal cross-section is determined from the minimum volume condition, against the three modal bucklings. More >

Mustafa Yidiz¹, Bayram Heydarov², İsmet Gölgeleyen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.62, No.3, pp. 255-264, 2010, DOI:10.3970/cmes.2010.062.255

Abstract We investigate the solvability of an inverse problem for the non-stationary general kinetic equation. We also obtained the approximate solution of this problem by using symbolic computation. A comparison between the approximate solution and the exact solution of the problem is presented. More >