ABSTRACT
Although a mechanical system is a collection of interconnected links, it is possible to describe a mechanical system as a collection of interconnected points or particles. The point-coordinate formulation is a generalization of a similar classical method in analyzing simple mechanisms. The equations of motion for a multibody system with the point-coordinate formulation have a similar form or structure as those of the body coordinates. The method enabled engineers, before the advent of computers, to perform a quick back-of-the-envelope analysis on a simple mechanism and obtain a general understanding of its response. The defined primary and stationary points that describe a multibody system are not completely free particles—they are dependent on one another through algebraic constraints. The distribution of the inertia of a planar body requires four primary points, and for a rod, it requires three primary points. This chapter learns how to eliminate the additional primary point from the formulation without jeopardizing the exactness of the mass distribution.
