Advanced Mode Shape Identification Method for Automotive Application via Modal Kinetic Energy Plots Assisted by Numerous Printed Outputs

Design optimization procedures of full-vehicle simulation models - such a procedure as shown in this paper - require a very fast and reliable mode shape identification. Just because these simulation models necessarily contain a lot of large concentrated masses and mass moments of inertia, e.g., engine, gear, differential, car wheels, steering wheel, mufflers, airbags, and reduced masses from superelement processing, to name just a few, the kinetic energy method is especially destined to accomplish this task. In the present paper, a graphical Modal Kinetic Energy evaluation technique is described in detail. Moreover, the modal kinetic energy plots are a means to investigate the structure's eigenbevior in the lowfrequency range, e.g., to see where dynamic vibration absorbers have to be attached and where bushings, and instrumentation for modal testing have to be placed. In summary, the presented graphs make even the most complicated subjects clear and provide the dynamicist with information he can use to achieve a better design quickly. The prints of significant values indicate the degree of coupling between energies in rotational and translational direction per mode and the energy portions of the physical residual chassis structure and the energy portions of appended body and subframe superelements. Representative applications for mode shape identification in automotive engineering, V70, are presented extensively in order to demonstrate the strength of the method. Surely, there are many other applications in the engineering structural analysis field where the advanced mode shape identification method will play key roles.