Impacts of Kinematic Links with a Granular Material

Abstract

The impact of kinematic links into a granular material is studied. In the impact process through the granular material defined as a conglomeration of discrete solids, the most important force governing the motion of a body is the resistance force of the granular matter. The resistance force acting on the body is studied as a linear superposition of a static (depth-dependent) resistance force and a dynamic (velocity-dependent) frictional force by considering the characteristics of the granular material acting like solid and liquid. The impact models considered are spheres, mathematical pendulum, compound pendulum, open kinematic chains, and elastic links. The impact is observed from the contact moment until the rest using various initial conditions. In this study, the impact angle and the initial velocity are the dominant conditions deciding the whole impact process. The results of the simulations and the experiments are analyzed based on the initial impact conditions. For most of the analyzed impact systems including elastic objects, the system under high force impact (higher initial velocity) comes to rest faster in the granular matter than the same system under low-force impacts (lower initial velocity).