Particle based methods such as the Discrete Element Method and the Lattice Spring Method may be used for describing the behaviour of isotropic linear elastic materials. However, the common bond models employed to describe the interaction between particles restrict the range of Poisson's ratio that can be represented. In this paper, to overcome the restriction, a modified bond model that includes the coupling of shear strain energy of neighbouring bonds is proposed. The coupling is described by a multi-bond term that enables the model to distinguish between shear deformations and rigid-body rotations. The positive definiteness of the strain energy function of the modified bond model is verified. To validate the model, uniaxial tension, pure shear, pure bending and cantilever bending tests are performed. Comparison of the particle displacements with continuum mechanics solution demonstrates the ability of the model to describe the behaviour of isotropic linear elastic material for values of Poisson's ratio in the range $0 \leq \nu < 0.5$.

中文翻译：

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粒子法描述各向同性线性弹性材料行为的改进粘结模型

基于粒子的方法（例如离散元素方法和晶格弹簧方法）可用于描述各向同性线性弹性材料的性能。但是，用于描述粒子之间相互作用的通用键模型限制了可以表示的泊松比的范围。为了克服这种局限性，提出了一种包含相邻键的剪切应变能耦合的改进键模型。耦合用多键术语描述，该术语使模型能够区分剪切变形和刚体旋转。验证了修正键模型的应变能函数的正定性。为了验证模型，进行了单轴拉伸，纯剪切，纯弯曲和悬臂弯曲测试。