Numerical Simulations of Particle Behavior and Crushing within a Pressurized Sand Damper Subjected to Cyclic Loading

Abstract

This paper presents a discrete element method (DEM) numerical model to elucidate mechanical behavior, particle crushing, and anisotropy evolution within a pressurized sand damper (PSD) subjected to cyclic loading. Computational simulations of the PSD under different initial pressures and stroke amplitudes were conducted and compared to experimental results. Good agreement was achieved between the DEM model and experimental results for the different cases. Force–displacement, particle crushing, shear, and normal stresses along with geometric and mechanical anisotropy degrees were closely monitored in different areas of the PSD. Dissipated energy was also monitored and used to calculate the specific damping capacity. Employing spherical particles, crushable clusters, and uncrushable clumps as sand particles revealed that the closest results to the experiments are obtained when using crushable clusters. The results show that the majority of crushing occurs in the vicinity of the center of the PSD and within the first loading cycle. Increasing stroke amplitude significantly influenced particle crushing, whereas increasing initial pressure was less considerable. In addition, a direct relationship between the PSD’s direction of movement with shear and normal stresses and anisotropy degree was observed. Moreover, the contribution of mechanical anisotropy was more considerable than the geometric anisotropy to the overall anisotropy degree. Regarding dissipated energy, an increase in stroke amplitude resulted in higher dissipated energy whereas an increase in initial pressure had a minor influence on the dissipated energy. Based on the dissipated energy, it was found that the specific damping capacity was nearly equal to one for all cases studied.