Parameterization Modeling And Lightweighting Design For Front Structure Of Body-in-white

In recent years, as the rapidly development of China’s automobile industry, automobile production and sales for many years more than 2000 million, by the year 2015 vehicle population has reached 279 million, which including 172 million automobile, The automotive industry has made a significant contribution to promote economic development.However, the negative effects brought by the rapid development of the automobile industry has become more and more serious, the oil shortage, deterioration of air quality, safety accidents, serious impact on the healthy development of human society. Energy saving,safety, environmental protection as the direction of the current auto industry, urgent demand for lightweight automobile has become a response to the above problems. Since the body structure possesses about 40% weight of full vehicle, and the body assembly has the advantages of simple structure, easily for lightweight optimization, therefore, the lightweight design of the body has become an important trend in the world of automotive development.Combined with actual project, a light-weighting design to a car body front structure has been carried out.Firstly, the SFE CONCEPT parameterization modeling was introduced, then the target vehicle body front structure model is established. And the parameterized front structure of BIW coupled with the finite element rear structure modal frequency, generated BIW model used for static bending and torsion stiffness and mode analysis; the body, engine, chassis and other models were connected, generated vehicle model for full frontal impact simulation analysis.The static bending and torsional stiffness, first bending and torsional mode frequency of the BIW, and the B-pillar acceleration of 100% frontal crash were carried out. All of the analysis results were compared with the initial finite element model. Through the comparison results, the accuracy of the car body front structure parameterization model was proved.Combined with optimization techniques,With the help of optimized design platform Hyperstudy, 14 design variables, such as the shape of the cross section and the thickness ofthe plate were chosen, the mass and the B pillar acceleration peak as the targets, the static bending and torsional stiffness, the first bending and torsional mode frequency of the BIW as the constraint。After the optimization process, got the optimized design scheme which design variables were engineering amended. Finally the mass of car body front structure was reduced from 100.2 kg to 95.04 kg, weight loss 5.17 kg, reduced by 5.2%, while static bending and torsion stiffness, first-order bending mode frequency performance decrease less than 3%, still meet the performance requirements, and the first-order torsion mode frequency,B pillar acceleration of 100% frontal impact has been optimized. The results indicated that the optimization obtained a well effect.