Research And Applications Of Model Simplification And Model Validation For Complex Engineering Systems

To design complex engineering system,traditional CAD model is usually complex,and it always takes lots of time and money to analyze the CAE model which is established on the CAD model.To solve this problem,CAD/CAE model simplification method is applied.Though there are lots of simplification methods,it still lacks a method which contains model simplification,model validation and optimization.To solve the problem,a design flow which contains model simplify method,EEARTH metric and robustness design is proposed.And a vehicle side impact simulation case is applied to show the validity of the method.The main researches of this paper are shown below:(1)A simplify method which contains geometrical feature extraction,model dimension reduction and sub-model extraction is proposed.And it's applied to deal with the CAD model in order to make it easier to mesh and reduce the grids in its CAE construction phase.Besides,sub-model extraction is applied base on the initial CAE model.(2)Model validation metric is investigated,EEARTH metric is proposed to validate CAE simplified model,and the detail of this metric is shown.(3)Modeling process is studied and a vehicle side impact model is applied as an example,the sub-model is established according to the correct integral CAE model.The accuracy of the simplified model and robustness of simplified model's boundary condition are evaluated by the EEARTH metric.(4)Apply the parameters which are gotten by DOE to the simplified model.By using the result of the simplified model,metamodel is set up and SA is applied to optimize the weight,finally,the original integral CAE model is used to validate the optimized result.The final conclusion is that: the simplification of CAD model can make the mesh of CAE model more smooth and reduce the number of the mesh.Sub-model of CAE model can save simulation time,meanwhile,EEARTH can quantity the accuracy of the simplified model.And the optimization of sheets' design based on the simplified model and metamodel is effective.