Modelling wave propagation in granular materials

Granular materials refer to a class of natural and synthetic materials consisting of individual particles that interact with each other when subjected to loading. These materials behave differently from usual solids and exhibit many salient features such as dilatancy, anisotropy, pressure dependence, density dependence, and nonlinear elasticity. The mechanical behavior of granular materials is a subject of long-standing interest in many fields, with both scientific fascination and practical importance. The proposed research will deal with a fundamentally important and difficult problem: wave propagation in granular materials. Traditionally, the relationship between wave propagation velocity and material stiffness is largely based on continuum theory, but many macroscopic response features result from the particulate nature of the material. This research is aimed to enhance our understanding of the nature of wave propagation in granular materials through a particulate approach.
Particular interests will be concerned with wave velocity, dispersion and attenuation of granular assemblies that have different characteristics (e.g. grading, particle shape and fines content). In this proposed research, discrete element method (DEM) is adopted as the numerical tool to explore the wave behaviours in granular materials at microscopic and macroscopic level. However, it is known that dealing with a large amount of particles is quite time-consuming. Therefore, the original code has been modified to achieve the expected states while still applicable to fast parallel computing and the high performance computing (HPC) will accelerate the simulations and shorten the overall time cost.