A MULTISCALE COMPUTATIONAL METHOD FOR 2D ELASTOPLASTIC DYNAMIC ANALYSIS OF HETEROGENEOUS MATERIALS

The elastoplastic dynamic analysis of heterogeneous materials is studied based on the multiscale computational method developed in our previous work (Zhang et al., 2013). The basic principles of this method are introduced briefly. To describe the complex deformation, a 2D multinode coarse element is proposed. In addition, to improve the computational accuracy for the dynamic problems, mode base functions are introduced into the multiscale numerical base functions to consider the dynamic effect of the structure. For nonlinear elastic or elastoplastic dynamic problems, the microscopic unbalanced nodal force cannot be projected to the macroscopic level effectively only by the displacement and mode base functions when the nonlinear material deformation occurs during the computation. So a correction technique of the local displacement is applied to deal with the unprojected microscopic unbalance forces within the coarse element. Furthermore, the computational procedures of a two-scale modeling are proposed within the framework of nonlinear dynamic analysis. Extensive numerical experiments are carried out and the results are compared with the traditional finite element method (FEM) which is applied directly on the fine-scale mesh. It is shown that the proposed multiscale method can obtain excellent precision of the nonlinear dynamic response of the elastoplastic heterogeneous materials. Moreover, the computation comparisons indicate that the proposed method spends less computer memory and CPU time than the traditional FEM.