Study On Stamping Process Of Aluminum Alloy Substituting For Steel In A-pillar Reinforcement Sheet Metal Part

With the development of automobile lightweight,aluminum alloys are increasingly being used in the lightweight of automobile panels.A-pillar reinforcing plate is a typical automotive panel.A pair of the parts is mounted symmetrically on the left and right side of car's body.It is an important strength and stiffness reinforcement for the auto body.This paper took the A-pillar reinforcing plate as the research object.The lightweight material of aluminum which substitutes for steel was studied.Firstly,Lightweight aluminum alloy material was chosen based on the performance requirements of the A-pillar reinforcement.A forward bending model was established based on the shell finite element theory.The influence of material properties and thickness changes of steel plate(BLD)and lightweight materials(AA6451-T4)on the forward bending stiffness of the parts was studied by simulation software.And the thickness of materials was designed based on the equal stiffness conditions.Then,based on the stamping theory and design experience of steel sheet covering parts,the drawing process model and technological parameters of A-pillar reinforcement were designed.By using the simulation software AUTOFORM,the different drawing properties of two kinds of metal under the same process parameters are analyzed.Based on the analysis,the drawing parameters of the aluminum plate were optimized by using the method of controlling the depth ratio.The drawing process parameters of aluminum panel parts were optimized by orthogonal test method.The production parts under optimized parameters were tested by strain measuring equipment,and the qualified products were obtained.Next,for the phenomenon of twist springback when stamping part was released from stamping die,was researched.The causes of twist springback was analyzed,the model of twist springback evaluation was established.By using the three dimension measuring instrument,the influence of the blank holder force on the twist springback of aluminum alloy for A-pillar reinforcement was studied,and verified.1700 KN is the best blank holder force for the panel part in stamping process.In this paper,the lightweight design of automobile panel parts was developed using aluminum instead of steel.The experience of stamping production of traditional steel plate parts was partly inherited to the production of aluminum plate parts.Numerical simulation method and experimental design method were used to optimize the process modeling and parameters optimization which will benefit for the lightweight design and stamping process for the similar automobile panel parts.