Study Of The Finite Element Spotweld Models Based On Modal Analysis Of Body In White

Because of the development of CAE technology, the efficiency in the process of vehicle R&D was promoted a lot. The application of CAE technology was more and more deeply applied, which put forward the results of CAE analysis accuracy to meet higher requirements.In this article, the author focued on the topic of the accuracy of spot weld type in modal analysis of BIW(body in white) simulation. The BIW finite element model, which used CFAST model for spotwelds simulation, was established to validate the modal analysis and experiment results. After then established the BIW finite element model, and adopt three types of spot weld model, including CWELD, CFAST and ACM2, to simulate spot welds. In the end, the accuracy of each type of spotweld model was compared.1) According to engineering experience, a variety of spot weld models were discussed in detail in the field of facility. Because different model had significant difference between the principle and structure, the author summarized the characteristics of each type of spot weld model, through a large number of engineering application.That can provide reference for the application of related areas.2) The A-class vehicle BIW FE model was established, and adopted Nastran for modal analysis. Meanwhile, modal experiment modal test was accomplished to validate the results.Then the FE analysis results and the experimental results were analyzed, by using statistical methods to evaluate the error. This method verified the accuracy and reliability of the finite element model.3) Evaluated the three types of typical BIW structure, named: two plates, double cap and single cap structure. Simplified the structures of each one, and then adopt the CWELD,CFAST and ACM2 model to do modal analysis. In the end, the FE analysis results and the experimental results were analyzed, to evaluate the accuracy of spot weld model.4) Finally, the author analyzed the whole BIW. Applied three kinds of spot weld model to do modal analysis of BIW, and compared with the test results. The application of statistical methods, was helped to analyze the simulation accuracy of the variety of spot weld model.Spot weld modes were verified by comparing of simulation and test results. The facility of each kind of spot weld model were discussed in detail.The conclusion and experience of this article could provide the reference for the application of each kind of spot weld model.