A finite element approach to dynamic modeling of multi-rigid body system

A approach is developed to model dynamic behaviors of multi-rigid Body system, the process is realized through concepts of equivalent element and equivalent system of force. Firstly, this paper develops the concept of element pseudo-mass matrix based on equivalent principle of element - generalized inertia matrix is equal to that of real component, and establishes pseudo-mass matrix of equivalent system through assembling units normatively, constraints of equivalent element and system is expressed by Jacobian matrix. Secondly, produces dynamical modeling equations based on generalized dynamical equation and concepts of equivalent system and system of forces, the expression is concise and standard and convenient for using with computer normatively. At last, the approach is used to generate the kinetic energy of crank guide mechanism and dynamical equations of 2-DOF robot manipulator, the results are the same as those of the traditional Lagrangian method.