Forward And Lightweight Design Of The Mixed Material Seat Frame Structure

In the overall plan of automobile development in "Made in China 2025",it is emphasized that "lightweight is still the top priority".Since the lightweight optimization of the passenger car seat is also significant of its role as the third largest assembly on the passenger car after the engine and chassis.For the lack of design method and process in seat frame lightweight,in this paper,a detailed optimization design method and a design process through introducing the toward design ideas of "CAE driven design" are proposed in car seat design phase for passenger car seat's lightweight optimization.And then based on a certain type of passenger car seat frame,a multi-objective lightweight optimization designs was carried out.Firstly,according to the ratio of energy absorption to mass method,the lightweight design components are selected.Secondly,different seat safety tests are conducted to optimize the corresponding components by considering both continuous thickness variables and discrete material variables.Thirdly,the strain index,the displacement of key points,the material cost,and the total mass of the components which need to be optimized are considered as objectives.After that,the grey relational analysis(GRA)is adopted to optimize the material-thickness scheme of the lightweight design components.Besides,the optimized coefficient of variation(OCV)method is applied to evaluate the corresponding weighting values of the objectives.Meanwhile,the availability of the grey relational analysis and optimized coefficient of variation(GRA&OCV)is assessed through comparing advantages among the method of GRA&OCV,the grey relational analysis and coefficient of variation(GRA&CV),technique for order preference by similarity to ideal solution and coefficient of variation(TOPSIS&CV),as well as technique for order preference by similarity to ideal solution and optimized coefficient of variation(TOPSIS&OCV)in the multi-objective lightweight optimization of passenger car seat frame.As a result,the total material cost and mass of the passenger car seat frame are reduced by 17.00% and by 2.08 kg(12.46%),respectively,with guaranteed vibrational and safety performance.Therefore,GRA&OCV can be effectively applied in multi-objective lightweight optimization of the passenger car seat frame.