EFFECTS OF MODE SELECTION, SCALING, AND ORTHOGONALIZATION ON THE DYNAMIC ANALYSIS OF FLEXIBLE MULTIBODY SYSTEMS

This paper analyzes the effects of mode selection, scaling, and orthog onalization on dynamic analysis of flexible mechanical systems. The ef fects of mode selection are investigated by combining attachment modes and constraint modes with vibration normal modes to represent elastic deformations of flexible components. Four sets of input data that dep end on the options for mode scaling and orthogonalization are generate d. The dynamic response and computer simulation times for each set are compared. Two examples are chosen: (1) a cantilever beam and (2) a ve hicle with a flexible chassis. With vibration normal modes and attachm ent modes, it was found that mode scaling was helpful for efficient si mulation, while the effect of mode orthogonalization was problem-depen dent. With vibration modes and constraint modes, however, mode scaling had no effect or detracted from numerical efficiency.