Study On Hydroforming Process Of The Strengthen B Pillar

The parts produced by the hydraulic forming process of pipe fittings have the advantages of high strength,low quality and cost saving.This paper combines the lightweight materials,the craft is lightweight and lightweight structure theory,aiming at more than welding B column reinforcing plate has carried on the comprehensive analys is of engineering application to retrofit for material is aluminum alloy A6610 series to strengthen tube expansion.Taking the T-tube as an example,the research steps of the fuzzy control system of the hydraulic bulging load path are introduced.Through the T-tube finite element model for analysis and processing,they can afford to determine the maximum internal pressure as a burst index,to match the internal pressure of the axial feed and int ermediat e punch displacement as the wrinkling indicators;Partition membership function;According to the molding quality,combined with Matlab and finite element simulat ion software and post-processing software to build fuzzy control system;The wrinkle index and the expansion crack index are used as input indicators for the fuzzy control system of T-tube.Multiple iterations have been obtained to obtain the effective loading path of T-tube hydraulic bulging.Improve the structure of B column and design the forming process.According to the function of B column,the lower end strength is required,so the hydraulic expansion of the lower end of B column is made to reduce the wall thickness and reduce the strength.In the case of a certain thickness of the tube,the section shape of the reinforced pipe is determined by comparing the thickness uniformity,thinning rate and strength characteristics of different cross-section tubes formed after the expansion.With regard to the symmetric way of the Bcolumn strengthening tube structure,c onsidering the difficulty of forming,the molding efficiency and the number of molds used,the three symmetrical methods tried in this paper are selected for selection.According to the shape characteristics of symmetrical structure,the process design of the reinforced pipe is designed,and the bending process,the mould process and the bulging process are finally determined.The fuzzy control system for the loading path of the hydraulic bulging process is built.There are three different types of wrinkling in the early,m iddle and late stage of the expansion process of B column,and different wrinkle indexes are formulated for different wrinkle types.In the expansion process,the wall thickness of the expansion zone is easy to reduce the swelling and crack phenomenon,so the thickness of the tube wall thickness is used as the index of expansion crack.B column strengthening pipe for large long tube structure,to ensure the final tubing fully fit after mold ins ide,if merely on wrinkling index and burst index,can not ensure the accuracy of the fuzzy control system,so the plastic index are introduced to improve stick mold precision;The above three indexes are used as the input indexes of the fuzzy controller of the hydraulic forming loading path of the b-pillar,and the incremental output index of the loading path is obtained after many iterations.