Research On Exact Geometry Based Analysis Of Two-dimensional Elastic Domain

The time and cost spent in the automobile body design stage accounts for more than 70%of the whole automobile research and development stage.Therefore,the design of automobile body is a crucial link in the whole automobile research and development.The application of CAE technology in automobile body design not only reduces the cost of automobile research and development,but also shortens the cycle of automobile research and development.As a kind of CAE method,finite element method has made great achievements in automobile body design.However,complicated mesh division makes the calculation efficiency of finite element analysis low,and the introduction of geometric error leads to the decrease of calculation accuracy.Therefore,the research of new algorithm is very essential for the development of CAE analysis of automobile body.The exact geometry based analysis method uses NURBS to describe the geometric model,which can accurately describe the geometric shape of the model.Compared with the traditional finite element method,it can effectively avoid complex mesh generation,reduce geometric errors and have high computational accuracy.In this paper,the two-dimensional elastic plane,plate and shell structures are simulated under the framework of isogeometric analysis and exact geometry quasi-conforming technology.The works are listed:(1)The quasi-conforming finite element method is introduced in detail,and the exact geometry based quasi-conforming framework is given.In the EGQC method,the geomet-ric shape is accurately represented by the CAD data based on NURBS and no additional preprocessing is required.The solution space adopts the traditional finite element poly-nomial approximation.The results of numerical examples show this method has high computational accuracy when dealing with two-dimensional elastic plane problems.(2)The two-dimensional elastic plane element and the Reissner-Mindlin shell element based isogeometric analysis framework are given,and numerical examples are com-pleted.The results of numerical examples show that this method is very suitable for the simulation of two-dimensional elastic plane,plate and shell structures.(3)In this paper,simplified models of automobile top cover and refueling hole cover plate are established.The static simulation simulation is carried out by using the method of isogeometric analysis and exact geometry quasi-conforming respectively.Numerical results show that the algorithm proposed in this paper is practical in the simulation of automobile body panel.The present work lays a solid foundation for the follow-up research of the exact geometry analysis method in the simulation of automobile body panel.