Ping’en Li¹, Xianyue Su^1,2, Youquan Yin¹

CMC-Computers, Materials & Continua, Vol.6, No.2, pp. 93-102, 2007, DOI:10.3970/cmc.2007.006.093

Abstract Based on the perturbation method, for flexural wave in cased hole in anisotropic formation, the alteration in the phase velocity caused by the differences in elastic constants between anisotropic formation of interest and a reference, or unperturbed isotropic formation is obtained. Assuming the cased hole is well bonded, the Thomson-Haskell transfer matrix method is applied to calculate the dispersion relation of flexural wave in cased hole in unperturbed isotropic formation. Both the cases of a fast and slow formation are considered where the symmetry axis of a transversely isotropic (TI) formation makes an angle with… More >

G. Q. Xie^1,2,3, X. Han², S. Y. Long³

CMC-Computers, Materials & Continua, Vol.6, No.1, pp. 1-12, 2007, DOI:10.3970/cmc.2007.006.001

Abstract A multi-walled carbon nanotube is modeled as a multiple-elastic cylindrical structure. The numerical-analytical method is adopted to analyze the characteristics of harmonic waves propagating along an anisotropic carbon nanotube. Each wall of the carbon nanotube is divided into three-nodal-line layer elements. The deflections of two adjacent tubes are coupled through the van der Waals. The governing equation of element is obtained from Hamilton's principle. A set of system equation of dynamics equilibrium for the entire structure is obtained by the assembling of all the elements. From solution of the eigenvalue equations, the dispersive characteristics, group More >

A. Wacher¹, D. Givoli²

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.3, pp. 147-164, 2006, DOI:10.3970/cmes.2006.015.147

Abstract The recently proposed String Gradient Weighted Moving Finite Element (SGWMFE) method is extended to include remeshing and refining. The method simultaneously determines, at each time step, the solution of the governing partial differential equations and an optimal location of the finite element nodes. It has previously been applied to the nonlinear time-dependent two-dimensional shallow water equations, under the demanding conditions of large Coriolis forces, inducing large mesh and field rotation. Such effects are of major importance in geophysical fluid dynamics applications. Two deficiencies of the original SGWMFE method are (1) possible tangling of the mesh… More >

J.T. Verbis¹, S.V. Tsinopoulos², D. Polyzos²

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.6, pp. 803-814, 2002, DOI:10.3970/cmes.2002.003.803

Abstract In the present work the iterative effective medium approximation (IEMA) is appropriately used for wave dispersion and attenuation predictions in fiber-reinforced composites that microscopically exhibit a non-uniform fiber distribution. Two types of composites with such irregular topology of fibers are considered. The first contains a regular distribution of clusters of fibers embedded in a composite matrix with uniformly distributed fibers, and the second a uniform distribution of matrix-rich inclusions embedded in a fiber-rich regular composite medium. The resulting from the application of the IEMA scattering problems are solved numerically by means of a two dimensional More >