三方程线性弹性-阻尼DEM模型及碰撞参数确定

Three-equation linear spring-dashpot DEM model and the determination of contact parameters

建立了一种考虑法向接触力、切向接触力(含静滑动摩擦力及动滑动摩擦力)和力矩(含由切向力产生的力矩及静滚动摩擦力矩和动滚动摩擦力矩)的三方程线性弹性-阻尼离散单元模型,并将该模型应用到颗粒物料的三维数值模拟中,讨论了模型中几个重要碰撞参数——刚性系数、阻尼系数及摩擦系数的选择及其对计算结果的影响,同时也探讨了时间步长等计算参数对模拟结果的影响。为了验证算法和参数选择的正确性,本文对几个有代表性的颗粒系统进行了数值试验研究,并对计算结果进行了细致的分析,验证了新模型和参数选择的正确性。

The three-equation linear spring-dashpot model for granular dynamics is a relatively complete discrete element method （DEM）, which takes full account of the particle-particle interactions, i.e. the normal contact force, the tangential contact force （including static sliding friction force and sliding fric- tion force） and the moment （including the moment generated by the tangential force, static rolling friction force and rolling friction force）. This paper applied the three-equation linear spring-dashpot model to the three-dimensional simulations of granular dynamics in some physical systems. The significance of the choice of contact parameters such as the contact stiffness, the damping coefficient, and the friction coefficient was discussed in detail. Experimental results were employed to validate the model predictions, especially the influence of the simulation parameters.