刚性块体压入颗粒体系时的受力及力链演变

颗粒体系由大量离散颗粒组成，普遍存在于自然界中，比如砂土地基、泥石流及滑坡体等。外荷载通常沿着准直形的路径在体系内传递，形成区别于单个颗粒和整个体系的细观结构--力链，亦即颗粒物质具有典型的多尺度特征。采用颗粒离散元方法模拟刚性块体压入颗粒体系的过程，计算得到了刚性块体底部所受阻力与压入深度的幂率关系；给出力链的判断准则和搜索强力链程序，构建颗粒体系强力链网络，并分析了压入试验过程中力链的演变及其长度的分布规律。

Evolution of force chains in a granular assembly based on indentation test

A granular assembly is a conglomeration of discrete solid and exists in nature widely, such as sand foundations, debris flows and landslides, etc. It is found that external loads generally transmit along the quasi-linear path in the granular assembly, and a special mesoscale structure between a single particle and the entire system, called a force chain, is formed. In other words, granular matter has the typical characteristics of multi-scale. A series of discrete element simulations are conducted on a static granular assembly subjected to indentation by a rigid flat punch. By proposing three conditions for defining a force chain, the evolution of the strong force chain network is presented. The distribution of strong force chain length during the indentation of the punch is also analyzed.