Abstract

The aim of this study is to introduce a stress-based non-binary contact model missing in classical discrete element method (DEM). To tackle this issue, a classical force-displacement contact law is generalized by utilizing the trace of the particle stress tensor to make all contacts dependent on all other contacts of a particle and thus, to account for multiple contacts simultaneously acting on a single particle. Simulation results for uniaxial confined (oedometric) compression employing our new multi-contact model were compared with the classical discrete element formulation, an existing strain-based multi-contact model, and experimental data. The satisfactory agreement between these results supports the validity of our new contact model. Several test examples at higher load levels show that our generalized contact model is able to capture the stronger non-linearity at higher stresses. Due to its simplicity, the proposed multi-contact model can easily be integrated in any DEM implementation, remaining relatively fast when compared to more complex methods or even a discretization of particles, e.g. by FEM.

Graphical Abstract

中文翻译：

---

基于应力的多触点模型用于离散元模拟

摘要

本研究的目的是介绍经典离散元方法（DEM）中缺少的基于应力的非二元接触模型。为了解决这个问题，通过利用粒子应力张量的迹线使所有接触都依赖于粒子的所有其他接触，从而考虑到同时作用于单个粒子的多个接触，来概括经典的力-位移接触定律。使用新的多触点模型对单轴约束（测压）压缩的模拟结果与经典离散元素公式，现有的基于应变的多触点模型和实验数据进行了比较。这些结果之间令人满意的协议支持了我们新的联系模型的有效性。在较高负载水平下的几个测试示例表明，我们的广义接触模型能够在较高应力下捕获更强的非线性。由于其简单性，建议的多触点模型可以轻松地集成到任何DEM实现中，与更复杂的方法甚至是粒子离散化（例如，通过FEM）相比，都保持相对较快。

图形概要