2维任意形状颗粒间的滚动阻力模型

Rolling Resistance Model between 2D Arbitrary Shaped Particles

本文将2维圆形颗粒间的滚动阻力模型推广到非圆形颗粒体系,用于模拟准静态剪切实验,得到了满足率无关和客观性的剪切、剪胀曲线。给出的滚动阻力模型对Hertz接触模型和线性接触模型是普适的,改变颗粒形状也是适用的,所得剪切、剪胀曲线和已有的实验符合;作为对比,将文献中几种常用的滚动阻力模型用于相同的体系,单一速度下的剪切、剪胀曲线和实验符合,但不同速度下的剪切、剪胀曲线却不重合即不满足准静态颗粒体系下的率无关,且所得有效摩擦系数偏小。滚动阻力对剪切强度、剪胀-剪缩影响显著,是必须考虑的相互作用,所给的任意形状颗粒间的滚动速度满足客观性且其特殊情形和圆形颗粒间滚动速度一致。

A rolling resistance model between circular particles was applied in non-circular particle system to simulate the quasi-static shear method for stress-strain and dilatancy curves that meet rate independence and objectivity. In addition,the rolling resistance model of arbitrary shaped particles is generally applicable for Hertz Contact Model,linear contact force model and changing particles shape. The stress-strain and dilatancy curves are also consistent with experimental results,which were compared with the shear curves calculated at a single speed under the same system in other rolling resistance models in previous researches. Results show that the shear curves do not coincide at different shear speeds,which means that the rate independence of the quasi-static particle system is not satisfied and the effective friction coefficient is smaller. Due to the remarkable effect of rolling resistance on the shear strength,the shear dilatancy and the shear contaction,the interaction between particles should be considered in simulation. The rolling velocity between arbitrary shaped particles meets the objectivity and it is consistent with the rolling velocity between circular particles under certain circumstances.