基于窗技术的多孔介质材料力学性质的数值均匀化方法
摘要
Compared with analytical homogenization methods, numerical homogenization methods can represent the complex mechanical responses of the detailed representative volume element (RVE), and can be used to identify the effective mechanical behavior of multi-scale materials of porous medium. However, linear displacement boundary conditions do not satisfy local equilibrium if void pores distribute at the boundary, thus the effective properties are questionable since unnatural stress concentrations occurs. Inspired by the self-consistent scheme from analytical micromechanics, the window (i.e., homogenized matrix) method is proposed in this paper. The RVE, obtained from the reconstruction method and the finite element implementation method, is evenly embedded in a matrix of average stiffness and linear displacement boundary conditions are applied to its boundary. Thus the homogenized properties of the porous medium become easily solvable and more reliable. In addition, the influence of the width of the window on the effective properties was discussed. Based on the available experimental data, the proposed scheme was carried out to deduce the macroscopic material property of concrete. The results show that the proposed scheme can enhance the credibility of the current numerical homogenization for mechanical behavior of porous medium.