Research On Design Method Of Tailor Welded Blank Based On Multiobjective And Multi-material Topology Optimization

With the gradual improvement of energy conservation policies and environmental protection requirements,automotive lightweight technology has become an important research topic in the current engineering field.At the same time,the competition in domestic and foreign auto markets has become increasingly fierce,and the overall performance requirements for auto parts and components have become higher and higher.The key to the lightweight design of auto parts structure is how to ensure that the auto parts meet their various performance requirements,improve the utilization of materials and achieve structural weight reduction design of the auto parts.In recent years,Tailor Welded Blank(TWB)technology has gradually been applied to the design of automobiles.By welding different types of materials or different thicknesses can effectively reduce the body mass and increase the local strength of parts,reduce manufacturing costs.At present,research on TWB technology mostly focuses on manufacturing,stamping process,and its welding performance.The TWB optimization design problem in practical engineering applications is less involved,and the research is not systematic enough and dee p enough.Some of TWB's key design factors such as the selection of materials,the determination of weld location,etc.are still dependent on the designer's personal experience,or are obtained by reference to other designs,so that the performance of the TWB structure can not be fully realized,TWB's The design level is still not high.In order to improve the optimal design level of TWB structure,a multi-objective multi-material topology optimization(MMTO)method is proposed in this paper.The topology optimization method is combined with TWB.Considering the constraints of the manufacturing process,different tailoring plates for different materials are determined according to the specific working conditions of the structure.Welds are optimally arranged.a Compromise Programming Approach(CPA),and the Mean Frequency Method(MFM)method are introduced to deal with multi-objective problems.The extended Bi-directional Evolutionary Structural Optimization(BESO)method is used to optimize.The proposed method was applied to the optimal design of the TWB indoor panel of the automotive.Under the premise of ensuring the stiffness and modal performance of the TWB door system meet the design requirements,the mass of door system was reduced by 12.8%,and the m ass of inner door panel was reduced more than 27.6%.The designed method can provide some useful guidance for the lightweight design of engineering and the rational arrangement of multi-material TWB structural welds.