Abstract The linear-slider-dashpot (LSD) soft sphere model is used extensively to model particle collisions in dense particle systems. The contact mechanics in the normal and tangential directions are modeled by a spring, damper, and dashpot system. The current work evaluates different existing tangential direction implementations of the LSD model. The existing models require storing the cumulative tangential displacement for each collision pair. The article evaluates existing tangential models and develops alternative methods which do not require storing the tangential deformation. The models are tested for two canonical single particle experiments of oblique impacts and sphere traveling on a surface. It is shown that some of the existing implementations fail to validate with at least one of the test cases. In one proposed model, Model-C, the tangential displacement is approximated as the product of the characteristic time of collision with the instantaneous particle tangential contact velocity. In a second proposed model, Model-D, the instantaneous non-dimensional impact angle is used to characterize the impact according to Maw et al.’s analysis. Both models give reasonably good predictions in the two test cases with the quality of predictions as good or better than some existing implementations which require the storage of the tangential deformation.

中文翻译：

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软球碰撞模型的替代切向冲击处理

摘要 线性滑块缓冲器 (LSD) 软球模型被广泛用于模拟密集粒子系统中的粒子碰撞。法向和切线方向的接触力学由弹簧、阻尼器和缓冲器系统建模。当前的工作评估了 LSD 模型的不同现有切向实现。现有模型需要存储每个碰撞对的累积切向位移。本文评估了现有的切向模型并开发了不需要存储切向变形的替代方法。这些模型针对斜向撞击和球体在表面上移动的两个标准单粒子实验进行了测试。结果表明，一些现有的实现无法通过至少一个测试用例进行验证。在一个提议的模型 Model-C 中，切向位移近似为碰撞特征时间与瞬时粒子切向接触速度的乘积。在第二个提出的模型模型 D 中，根据 Maw 等人的分析，瞬时无量纲冲击角用于表征冲击。两种模型在两个测试用例中都给出了相当好的预测，预测质量与一些需要存储切向变形的现有实现一样好或更好。