Modal analysis of semi-trailer BIW

The BIW of a semi-trailer was chosen for this study, and the finite element model of this BIW was established, achieved the modal parameters by both simulation and test. It found out that the frequencies between simulation and test are quite different. To find out the reason of the difference, designed an airbag tooling which can provide more accurate free mode boundary, carried out modal experiment again. Turned out the deviation between simulation and test are very small, which shows that the modal test boundary has a great influence on the results and the airbag tooling designed in this paper can effectively improve the accuracy of modal test. It also shows that the FEA modeling method and analysis method are feasible, which can provide a reference basis for the structural design and dynamic characteristic optimization of BIW.