Open Access
ARTICLE
A.N. Guz1, J.J.Rushchitsky1, I.A.Guz2
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.3, pp. 139-156, 2008, DOI:10.3970/cmes.2008.026.139
Abstract The basic approach is offered for problems of nanocomposites and their mechanical properties, which includes a short review of modern problems in nanomechanics of materials. The fibrous carbon-polymer composites with carbon or graphite microfibers or carbon nanotubes are especially discussed. The basic model of the linear or nonlinear elastically deforming micro- and nanocomposites is considered. Within the framework of this model, the comparative computer modeling is performed. The modeling permits to observe the features in prediction of values of basic mechanical constants. These results are utilized on next step of modeling -- studying the peculiarities of wave propagation in particular… More >
Open Access
ARTICLE
Chein-Shan Liu1
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.3, pp. 157-168, 2008, DOI:10.3970/cmes.2008.026.157
Abstract For the Sturm-Liouville eigenvalues problem we construct a very effective Lie-group shooting method (LGSM) to search the eigenvalues, and when eigenvalue is determined we can also search a missing left-boundary condition of the slope through a weighting factor r ∈ (0,1). Hence, the eigenvalues and eigenfunctions can be calculated with a better accuracy. Because a closed-form formula is derived to calculate unknown slope in terms of λ for the estimation of eigenvalues, the present method is easy to implement and has a low computational cost. Similarly by applying the LGSM to find a corresponding eigenfunction in terms of λ is… More >
Open Access
ARTICLE
Thi D. Dang1, Bhavani V. Sankar2
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.3, pp. 169-188, 2008, DOI:10.3970/cmes.2008.026.169
Abstract In this paper the meshless local Petrov-Galerkin (MLPG) method is used in the micromechanical analysis of a unidirectional fiber composite. The methods have been extended to include shear loadings, thus permitting a more complete micromechanical analysis of the composite subjected to combined loading states. The MLPG formulation is presented for the analysis of the representative volume element (RVE) of the periodic composite containing material discontinuities. Periodic boundary conditions are imposed between opposite faces of the RVE. The treatment of periodic boundary conditions in the MLPG method is handled by using the multipoint constraint technique. Examples are presented to illustrate the… More >
Open Access
ARTICLE
G.F. Karlis1, S.V. Tsinopoulos2, D. Polyzos3, D.E. Beskos4
CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.3, pp. 189-208, 2008, DOI:10.3970/cmes.2008.026.189
Abstract A boundary element method, suitable for solving two and three dimensional gradient elastic fracture mechanics problems under static loading, is presented. A simple gradient elastic theory (a simplied version of Mindlin's Form-II general theory of gradient elasticity) is employed and the static gradient elastic fundamental solution is used to construct the boundary integral representation of the problem with the aid of a reciprocal integral identity. In addition to a boundary integral representation for the displacement, a boundary integral representation for its normal derivative is also necessary for the complete formulation of a well-posed problem. Surface quadratic line and quadrilateral boundary… More >