ABSTRACT
Does granular material show strain rate-dependent response, especially with quasi-static loading conditions? The answer is both yes and no since it depends on various factors like particle shape, size and crushability. Such time-dependent behaviour in granular materials is extremely important in various industries where both particle crushing and loading rates are combined. The focus of the research has been to numerically exploit the strain rate effects at the grain scale level and link it with macroscopic response while simultaneously taking into account the evolution of particle size distribution during the fragmentation process. The numerical simulation of one-dimensional (1D) compression shows quasi-static loading, which presumably produces a rate-independent response, and can demonstrate significant rate-dependent features during particle crushing. The variation in the contact force distribution within the granular assembly at different loading rates, dictates the stress response and the crushing events. Relatively low strain rate compression favours homogeneous crushing involving a large number of particles that consequently reduces the strength via fragment rearrangement. Conversely, a high strain rate promotes localized crushing within fewer particles, and thus strain hardening is observed.
