Numerical simulation of the force output of a pressurized sand damper under cyclic loading

Abstract

This study implements the discrete element method (DEM) to capture the mechanical behavior of a pressurized sand damper (PSD) and characterizes the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability to dissipate energy through interparticle contact sliding. DEM employs a simple linear contact model for the entire assembly and utilizes irregularly shaped particles to mimic the behavior of sand grains. The series of DEM simulations reported herein examine the effects of multiple parameters on the magnitude of dissipated energy. These parameters include stroke amplitude, grain size distribution, the magnitude of pressure imposed on the sand, and different geometric configurations of the PSD. The results reveal that the main energy dissipation mechanism is interparticle frictional sliding in the sand. Moreover, when multiple spheres are attached to the piston rod significant increase in the magnitude of dissipated energy is achieved. The numerical results compare favorably with experimental data recorded from a PSD that was subjected to cyclic testing.