不同滚动摩擦模型下直板牵引的离散单元法仿真分析

Discrete Element Simulations of Soil-blade Interaction with Different Rolling Friction Models

在直板牵引条件下,以离散单元法的不同滚动摩擦模型(无滚动摩擦模型、常量滚动摩擦模型与弹簧阻尼滚动阻力模型)为对象,分别对其直板工具作用力以及牵引直板前粒子堆积形态进行了仿真分析,并研究了不同直板插入深度下不同滚动摩擦模型对直板工具作用力的影响。结果表明:不同滚动摩擦模型对直板牵引力影响不大,但对直板前粒子堆积形态影响较大,弹簧阻尼滚动阻力模型的仿真结果与经典土力学试验理论(直板插入深度与直板牵引力拟合直线的斜率成正比关系)高度吻合。弹簧阻尼滚动阻力模型具有更柔性地表达粒子间动力学微观机制与粒子集合宏观特性的功能,即更具有其牵引力与土壤破坏形态同时与试验结果吻合的可能性。

A discrete element method is used to study the effects of different rolling friction models( without rolling friction model,constant rolling friction model and spring-dashpot rolling resistance model) on the blade interaction force and particle pile geometry in front of the blade. Results show that rolling friction model has little influence on blade interaction force and significantly influences particle pile geometry. The results of spring-dashpot rolling resistance model fit the traditional passive soil pressure theory best. The springdashpot rolling resistance model can robustly describe microscopic particle interaction dynamics and macroscopic properties of particle assembly,and can produce results which fit the experimental results both in the form of blade interaction force and particle pile geometry.