Dynamics of few Practical Mechanisms using Multibond Graph

Abstract

ix newlineABSTRACT newlineModeling of mechanisms is important from the perspective of design and analysis. It is an inexpensive way to experiment with a system, to study the behavior of the system, and to design appropriate control systems before prototyping it. newlineIn case of multibody mechanisms, dynamic forces and moments, including their transients due to jerky or discontinuous motion, occur frequently. These transients are often incorrectly neglected at the design stage due to improper modeling. These dynamic forces and moments can be determined analytically and by simulation of a model of the actual system. newlineFor dynamic analysis of a multibody mechanism, its mathematical modeling newlinebecomes the first step. Different formulations such as the Newton-Euler, Lagrange- newlineEuler, Hamilton s, Kane s method, and Boltzmann Hamel s approach have been presented in literature by which the equations of motion of a multibody system can be obtained. newlineThe energy based formulations used for modeling usually tend to be too newlinemathematically inclined and cumbersome for large multibody systems. newlineMoreover, they do not reveal the physical aspects of the system in terms of cause and effect relationships (causality). newlineThe bond graph modeling technique, a graphical alternative approach, created by Henry Paynter in 1959, successfully overcomes these difficulties. It serves as an newlineappropriate approach for modeling physical system dynamics in multiple energy domains. Bond graph offers an opportunity for representation and analysis of causality, which is an important aspect of physical systems. This feature is not newlineoffered by the energy-based formulations. newlineIt has been established that various formulations, direct and energy-based, can be derived algorithmically from the bond graph model by appropriate causality assignment procedures and then following causal paths. newlineThe bond graph approach has been used by researchers to model the dynamics of various mechanical systems. Multibond graph modeling for analysis of dynamics, newlineespecially in the case of metal sawing mechanism