Uniqueness of Discrete Element Simulations in Monotonic Biaxial Shear Tests

Abstract

The discrete-element method (DEM) is an important tool for understanding the underlying microscale processes that influence macroscale behavior. For quasi-static simulations, numerically imaginary input parameters such as strain rate and damping constant can have significant influence on the resulting shear behavior, especially after the peak strength condition is attained. Consistent results require small unbalance forces among the particles, expressed as an unbalanced resultant force index. The unbalanced resultant force index is roughly proportional to the strain increment and inversely proportional to the average ratio of the particle overlaps and diameters and the ratio of the mean stress and the normal spring constant.