Reduction of Mode Observation Work in High Mode Density Range as Automotive Booming Noise by Mode Grouping

An approach to efficiently analyze many modes for forced vibration by mode grouping is proposed. This is an evolutionary application of the previous study [1] to automotive body with high mode density.

Ongoing progress of simulation technology on noise and vibration (NV) by Computer Aided Engineering (CAE) has extended frequency range. Although this progress is welcomed by NV engineers and is desirable for automobile development, it requires engineers to spend much time for examining many mode shapes and so on.

Usage of a concept of mode grouping was proposed to break the deadlock [1]. This concept was based on similarity of the effects of modifications, which were made on the noticed portions of the structure. However this approach was insufficient to actual automotive body structure because of inadequate estimation of frequency response sensitivity in high mode density et cetera.

In this study, practical techniques are added to improve the insufficiencies. The approach of mode grouping is refined through the application to an actual automotive body structure.