离散颗粒多尺度分级模型与破碎模拟

在所建议传统离散颗粒模型基础上引入了多尺度分级模型，定义了不同尺度的基本颗粒和颗粒簇模拟颗粒破碎现象．在统计断裂力学Weibull分布公式基础上利用名义应力给出了多尺度分级模型意义下颗粒破碎概率；结合颗粒簇的解簇模型建议了一个可模拟颗粒破碎的多尺度分级离散颗粒模型．数值例题初步显示了所建议模型模拟颗粒破碎现象的有效性．并利用所提出的名义有效应变和名义体积应变显示了颗粒破碎过程对颗粒材料结构物变形的影响．

Hierarchical multi-scale discrete particle model and crushing simulation

Based on the proposed conventional discrete particle model, a hierarchical multi-scale model for granular materials, in which basic particles and particle clusters are defined for simulation of particle crushing in different scales, is introduced. The particle crushing probability in the model is derived on the basis of the Weibull distribution formula in the frame of statistical fracture mechanics with the use of the nominal stress concept. With the de-cluster mechanism of the granular clusters introduced into the model, the proposed model can be used to simulate particle crushing phenomenon in failure analysis of granular materials. Numerical results demonstrate the validity of the preceding model and exhibit the influence of particle crushing process upon the deformation of the structure of granular materials by using the proposed nominal effective and volumetric strains.