关键词: 离散单元法, 滚动摩擦, 塑性变形, 接触模型

Abstract: As the original spring-damper rolling resistance model cannot accurately express the change of the deformation of plastic materials，this paper presents a new rolling resistance model based on discrete element for plastic materials，namely the hysteresis torque rolling resistance model． In this model，based on the elasto-plastic deformation theory of particle materials，the rolling resistance torque of the discrete element particles is described as a hysteresis term and a damping term． The hysteresis term expresses the force imbalance caused by the state that the front half of the contact portion is in the deformation process and the latter half in the recovery process，while the damping term expresses the friction on particle surface． The presented rolling contact model is then verified by a particles pile test and achieves a more accurate expression of the unbalanced plastic deformation state on both sides of the particle contact center． From the viewpoint of microscopic process of particle contact，the proposed model is more consistent with material's elastic-plastic deformation mechanism and can be widely used to simulate plastic materials

Key words: discrete element method, rolling friction, plastic deformation, contact model