DEM modelling of granular materials during cyclic loading
This paper summarises the potential of the Discrete Element Method (DEM) to simulate the behaviour of granular materials under cyclic loading conditions. DEM simulations were carried out on two different assemblies of granular particles (e.g. sand and ballast). It is shown that DEM is capable of simulating the cyclic behavior of granular materials (e.g. liquefaction, post liquefaction and cyclic densification of ballast) similar to the laboratory experiments. Moreover, an instrumented track at Bulli, NSW, Australia, was modeled using DEM to examine the lateral movement of granular materials, including the particle breakage during cyclic loading. The results of these simulations captured the lateral response of ballast in accordance with the field observations and the evolution of micro-mechanical parameters such as a distribution of the contact force and bond force developed during cyclic loading is presented to explain the mechanism of particle breakage.