Open Access
ARTICLE
Cao Guohua1, Zhu Zhencai1, Peng Weihong2, Wang Jinjie1, Liu Zhi1
CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.2, pp. 119-138, 2013, DOI:10.3970/cmes.2013.094.119
Abstract The single helical structure is twisted by surrounding helical units with clearance or not between two layers. In order to master the thermal expansion behavior, the theory has been developed for the analysis of these helical structures. The previously deduced linear expressions of thermal expansion coefficients for the gapless structure model (GM) is used and the analytical method is applied to the clearance structure model (CM) and clearance-gapless structure model(CGM) under two boundary conditions. For further evaluating the analytical expressions of two models, the finite element models of the single helical structure surrounding by helical units with lang lay and… More >
Open Access
ARTICLE
Guizhong Xie1, Jianming Zhang1,2, Cheng Huang1, Chenjun Lu1, Guangyao Li1
CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.2, pp. 139-157, 2013, DOI:10.3970/cmes.2013.094.139
Abstract In this work, an improved exponential transformation is presented for nearly singular boundary element integrals in problems of thin structures. Accurate evaluation of nearly singular integrals is an important issue in the implementation of boundary element method (BEM) for thin structures. In this paper, the exponential transformation, which was firstly developed to evaluate nearly singular integrals arising in 2D BEM, is extended into 3D BEM to deal with nearly singular integrals. Firstly, a novel (α,β) coordinate system is introduced. Then, the conventional distance function is modified into a new form in (α,β) coordinate system. Based on the refined distance function,… More >
Open Access
ARTICLE
Dan Dumitriu1, Ligia Munteanu1, Cornel Brişan2, Veturia Chiroiu1, Rǎzvan-Vlad Vasiu2, Octavian Melinte1, Victor Vlǎdǎreanu1
CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.2, pp. 159-173, 2013, DOI:10.3970/cmes.2013.094.159
Abstract The continuum modeling of tire/road vibro-contact dynamics is developed in this paper by assuming continuum relationship between the contact force and the deformation. An important aspect of this model is that the damping depends on the indentation. In the continuum approach, no difference is made between impact and contact, and the friction law can be other than the Coulomb’s law. Since the road is rocky, a bristle model was chosen to take into account the effect of the road irregularities. The identification of the contact domain is performed by checking the minimum distance between bodies. More >
Open Access
ARTICLE
Chia-Cheng Tsai1,2, D. L. Young3
CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.2, pp. 175-205, 2013, DOI:10.3970/cmes.2013.094.175
Abstract It is well known that the method of fundamental solutions (MFS) is a numerical method of exponential convergence. In this study, the exponential convergence of the MFS is demonstrated by obtaining the eigensolutions of the Helmholtz equation. In the solution procedure, the sought solution is approximated by a superposition of the Helmholtz fundamental solutions and a system matrix is resulted after imposing the boundary condition. A golden section determinant search method is applied to the matrix for finding exponentially convergent eigenfrequencies. In addition, the least-squares method of fundamental solutions is applied for solving the corresponding eigenfunctions. In the solution procedure,… More >