Research On Flanging Forming Of Aluminum Alloy For The Product Design

With the increasing concerns over energy crisis and environmental problems,light-weight development of automobile becomes the inevitable road of automobile industry.Because of its light low density,high strength,outstanding corrosion resistance,the proportion of aluminum alloy used in bodywork shows a trend of increasing year by year.However,due to the large differences in the properties between aluminum alloy and steel plate,it brings a lot of new problems to the product design and manufacturing process at the same time.Springback is one of the most important defects of body stamping,especially for the aluminum alloy,because the elastic modulus of aluminum alloy is only 1/3 of the steel plate,so the rebound of aluminum alloy is much larger than steel plate in the same condition.As for the flanging forming process of aluminum alloy,the flow and deformation behavior of sheet metal is more complicated in the process of forming,which makes it more difficult to control the springback in flanging.Combining finite element method,statistical theory and optimization theory to make optimum design is an important method to optimize sheet metal forming,Research shows that most of the manufacturing defects are related to unreasonable product design,and these unreasonable designs often can be found in the debugging of mold.If these problems are solved by the technology solution,the efficiency is not high,and the production cost is increased.At this time,the simultaneous engineering of product is particularly important.Therefore,it is one of the most effective ways to control the springback of aluminum sheet by controlling the springback of parts in product design stage.Based on this,this paper attempts to explore the optimization method of aluminum alloy flanging springback for product design.The main contents of this paper are as follows:Firstly,introduced the present state of the application of aluminum alloy for automobile body and the research status of aluminum alloy flanging process,and highlighted the significance of optimum design of product when solving the forming defects,raised the topic and research content.Secondly,introduced the basic theory of aluminum alloy stamping forming,and introduces the basic principle and evaluation method of flanging springback.Thirdly,analyzed the influence of different structural parameters on flanging springback by means of numerical simulation,and summarized the rules of product design.Then,based on the method of simultaneous engineering,the optimization method of aluminum alloy flanging springback for product design is proposed,and the steps and advantages of the optimization method were introduced in detail according to the theory of grey relational analysis.Finally,taking the aluminum alloy inner panel as research object,a finite element model for the flanging and springback process was established with FE software ABAQUS.In order to reduce the springback and the risk to crack,the character parameters and process parameters were optimized,the character parameters include upper bending radius,lower bending radius and flange angle,and the process parameters include friction coefficient and die clearance.The method combined orthogonal test and grey correlation analysis to transform multi-objective parameter optimization problem into a single target problem and got the better parameter to guide product design,and it was experimentally validated.