Modal Hammering Test and Sensitivity Analysis for BIW Vehicle

Aiming at the defects of classical modal parameter estimation approach, the impulse hammer modal test during body-in-white (BIW) stage was done through polyMAX method method. Based on modal analysis theory, an experimental model of BIW was established. The compositions of the experimental modal testing system, the design of testing scheme as well as its validation were described in detail in this paper. The collected data were identified via the polyMAX modal analysis method. The dynamic characteristics of BIW were confirmed by Modal Assurance Criterion. Influence of low frequency distribution characteristics on complete vehicle NVH was also analyzed. On the basis of above investigation, sensitivity analysis of the structure of BIW was conducted and sensitive structural parameters were determined. The test results show that the modal testing system can meet the requirement of precision with reliable results of parameter identification and sensitivity analysis, which can serve as a basis for the improvement of BIW structural design.