FE Model Updating And Optimization Analysis On Body-in-white

CAE technology, representatively FEA method, plays a more and more important role in the design of modern car products along with the development of computer technology and numerical calculation theory. It almost covers the most field of car design work. The unitized car body has been widely used in modern cars, which bears the whole loads from other parts of car. It meets the demands of weight reduction and energy saving, but also has high requirements of mechanical capabilities, both statically and dynamically, such as stiffness and modal capabilities.The precise finite element model plays a key role in dynamic structure design, and there are always errors in finite element modeling, so it is necessary to decrease the deviation between the simulation results and testing results. In this paper, the finite element model of the body-in-white of a car is established mainly using the shell element. Then the low-order modal parameter is gotten through calculation, Based on the modal testing results, the finite element model is updated through adjusting the connective stiffness between parts, to obtain a mathematics model that agrees with the actual mechanical characteristics of structure.In this paper, on the basis of the frequency and modal shape and of static characteristics, the sensitivity analysis of both static vertical bending stiffness and dynamic modal is performed. Finally, based on the sensitivity analysis results, the sensitive parts are picked up to conduct optimization analysis of this model.