Introduction

Through simulation of multibody systems as explained in the preceeding chapters, we can solve a variety of useful problems with no further enhancement. However, with the methods explained so far, we still lack the capability to simulate collisions, either between moving bodies or between a single moving body and its fixed surroundings. Simulation software developed strictly with the formulae presented so far assumes that a moving body may simply pass through others with no interference or impact. Clearly, this can benefit from enhancement.

Collision or contact between bodies cannot be detected unless it is through computations relating the geometries of the bodies’ surfaces. Therefore, we must have accurate geometric shapes for all bodies for which collisions are to be considered, and in as much detail and accuracy as we wish to monitor their possible contact. We need data for vertices, edges, and surfaces, and we need to distinguish the material from the exterior sides of such surfaces. Therefore, we need solid models of the bodies to be considered. Either constructive solid geometry (CSG) or boundary representation (B-Rep) or hybrid combinations may be considered, but wire-frame data are not sufficient.