二维多尺度颗粒材料受压性能数值模拟

Numerical Simulation of Two-Dimensional Multi-Scale Granular Materials Compression

颗粒材料的宏观力学行为是微观单个颗粒之间相互作用的结果。本文采用多尺度研究方法对已有试验进行了数值模拟,即在微观尺度下,采用离散元方法(DEM)对代表性结构单元(Representative Element Volume(REV))进行建模计算,在宏观尺度下采用有限单元法(FEM)进行求解。对FEM模型中高斯点处REV施加某一给定加载历史,采用均质计算方法获得REV全局应力张量,通过该应力张量推导FEM在每个高斯点的刚度矩阵,从而推导颗粒材料宏观数值本构响应。本文同时考虑了孔隙率,加载速度对压缩效率的影响。

On the macro-level, the behavior of granular materials is the consequence of the interactions of indi- vidual grains at the micro scale. A two-scale approach of computational homogenization is considered. At the micro scale, we consider granular structure REV （ Representative Element Volume ） modeled by the Discrete Element Method （ DEM ）. On the macro scale, the problem is solved by Finite Element Method （ FEM）. The upsealing technique is that using the response of REV at each Gauss point of the FEM ＇ s formulation to derive the constitutive response through the global stress and strain tensor of the REV. The porosity and velocity of loading are both taken into account.