Open Access
ARTICLE
Chein-Shan Liu1
CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.2, pp. 77-94, 2008, DOI:10.3970/cmes.2008.028.077
Abstract The method of fundamental solutions (MFS) is a truly meshless numerical method widely used in the elliptic type boundary value problems, of which the approximate solution is expressed as a linear combination of fundamental solutions and the unknown coefficients are determined from the boundary conditions by solving a linear equations system. However, the accuracy of MFS is severely limited by its ill-conditioning of the resulting linear equations system. This paper is motivated by the works of Chen, Wu, Lee and Chen (2007) and Liu (2007a). The first paper proved an equivalent relation of the Trefftz method and MFS for circular… More >
Open Access
ARTICLE
Chun Yang1, Dalin Tang2, Chun Yuan3, William Kerwin2, Fei Liu3, Gador Canton3, Thomas S. Hatsukami3,4, Satya Atluri5
CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.2, pp. 95-108, 2008, DOI:10.3970/cmes.2008.028.095
Abstract Atherosclerotic plaque rupture and progression have been the focus of intensive investigations in recent years. Plaque rupture is closely related to most severe cardiovascular syndromes such as heart attack and stroke. A computational procedure based on meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating patients were scanned three times (T1,T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Since there was insufficient… More >
Open Access
ARTICLE
X.Y. Cui1,2, G. R. Liu2,3, G. Y. Li1, X. Zhao2, T.T. Nguyen2, G.Y. Sun1
CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.2, pp. 109-126, 2008, DOI:10.3970/cmes.2008.028.109
Abstract A smoothed finite element method (SFEM) is presented to analyze linear and geometrically nonlinear problems of plates and shells using bilinear quadrilateral elements. The formulation is based on the first order shear deformation theory. In the present SFEM, the elements are further divided into smoothing cells to perform strain smoothing operation, and the strain energy in each smoothing cell is expressed as an explicit form of the smoothed strain. The effect of the number of divisions of smoothing cells in elements is investigated in detail. It is found that using three smoothing cells for bending strain energy integration and one… More >
Open Access
ARTICLE
Atsuya Oishi1, Shinobu Yoshimura2
CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.2, pp. 127-146, 2008, DOI:10.3970/cmes.2008.028.127
Abstract This paper describes new methods based on genetic approaches for finding approximating expressions of local coordinates of a contact point in a local contact search process. A contact search process generally consists of the following two phases: a global search phase for finding the nearest node-segment pair and a local search phase for finding an exact local coordinate of the contact point within the segment. The local contact search can be regarded as the mapping from the coordinates of nodes to the local coordinates of contact points. In this paper, two methods are proposed to find mathematical expressions that approximate… More >