Research Of CAE Modeling Method About Car Body Based On Equivalent Model

The intensity of competition made the body design corporation know that more and more clearly, if you want occupy more part of market, you should make new good product much more quickly. So, as a tool that will shorten the period of design, it has been more and more used in every process in product design and manufacture, to enhance the advantage of the product.Generally, the auto design fall into three phases, concept design phase and particular design phase. Concept design phase plays a very important roll in the auto design process. The well work of concept design phase is one key to reduce the period of design process. So, in the concept design phase, a concept model is needed for intensity, rigidity, and reliability analysis. It is simple, but it can reflect the characteristic of body, and also have change space for particular design phase. It can be used for whole body analysis, to design the structure and mode response. In the overseas auto corporation, CAE is not only a verify tool, but also be used as a design tool in the primary design phase, the particular degree is different along with the design phase change. The model in concept design phase can reflect the characteristic of body, and also have change space for particular design phase. At home, there is little research on'CAE modeling in concept design phase', in some researches, they only verify the feasibility of this method, there is no research on the modeling method. And in the past CAE model in concept design phase, the floor and Dash board was figured as plane, actually, there is many ribs on them, and these ribs influence the rigidity intensively, the precision of model will be reduced if ignore them.Against that, the author does the research of CAE modeling method in concept design phase, and ribs equivalent method. Finally, have some conclusions.First, use this ribs equivalent method, the rigidity ratio is only relate to the ratio of rib's width and depth, and accretion with the ratio rise.When adjust the section parameter use this method, we should improve the precision, the method is multiply the section parameter a coefficient. We get the formulary to calculate the coefficient, it is:There,'x'is the coefficient,'a'and'b'is the rib's width,'h'is its depth. Aside, the influence of the rib to the whole body rigidity is very small, but the influence of the rib to the local transmutation is very big, to research its equivalent is necessary.Computer simulation testing methods has incomparable superiority; however, computer simulation is still not completely out of the test or completely replaced the test. This is because the automobile entire vehicle or human models that established with computer simulation methods, have many inherent limitations, it is impossible to reflect the true process, so the validity of the results of computer simulation needs the test give final certification. In the paper, the author designs many experiments to validate the precision of the simulation. They are the BIW bend rigidity test, the BIW torsion rigidity test, and bend rigidity test of board with rib. According to the simulation and test result, the CAE modeling method in concept design phase and ribs equivalent method is feasible.Use this method; we can design a simple but also precise model in concept design phase. And the ribs equivalent method make the model precision improve obviously.