On the Local and Global Deformation Mechanism of Granular Haterials

对等直径规则排列的圆形单元组合体进行了刚塑性分析，以考虑粘性颗粒材料的细观和宏观机制之间的关系。单元没有弹性常数，但考虑了接触点的滚动和塑性滑动。用线性规划法求解临界状态下的单元平衡方程，以使所施加的力的上界最小。将部分变形模式与使用一组硬币的实验结果进行了比较。主要结果有：1）利用摩擦角和粘聚力对规则排列的圆形单元进行了刚塑性分析。2.数值分析的速度场的一些结果证实，无论是单元的位移还是旋转，都与简单实验的结果相似。3.分析所需的材料常数可以通过简单的实验获得。4.对承载力问题进行了比较，得到了一些有趣的解释。砂等岩土材料的真实的微观结构比本文的结构要复杂。除建立稳定快速的数值计算格式外，还需要考虑静摩擦和滚动摩擦、初始状态的随机构形、不同直径和不同s的单元的混合等因素的影响，并结合线性规划方法建立数值计算格式。

A rigid-plastic analysis of an assembly of regularly arranged circular elements with an equal diameter is performed to consider the relationship between the micro-and macro-mechanisms of cohesive granular materials. No elastic constant for elements is employed while rolling and plastic sliding at the contact points are considered. The equations of equilibrium of elements at the critical state are solved by using the linear programming method to minimize the upper bound of the applied force. Some of deformation modes are compared with the results of an experiment where a set of coins are used. The main results are :1)The rigid-plastic analysis of regularly arranged circular elements is done employing the frictional angle as well as the cohesion.2.Some results of velocity field by the numerical analysis are confirmed to be similar to those of simple experiments in both displacement and rotation of elements.3.The material constants necessary for the analysis can be obtained by a simple experiments.4.The comparison was done for the bearing capacity problem and some interesting interpretation was obtained.The real microscopic structures of such geotechnical materials as sands are more complicated than those in the present paper. Detail investigation is required to consider the effects of the static and rolling frictions, the random configuration at the initial state, the mixing of elements with different diameters and s, besides to establish the stable and fast numerical calculation scheme combined with the linear programming method.