Research On The Forming Limit Of Automotive Sheet Under The Engineering Environment

Sheet stamping forming technology is widely used in the field of automobile manufacturing.The stamping forming limit is one of the important indicators to evaluate the automotive sheet forming performance.Carrying out the forming limit performance test is helpful to understand the basic forming characteristics of the material and the feasibility of the part manufacturing process.However,the traditional material performance testing technology has the problems of low accuracy,low test efficiency,and failure to reflect the forming limit of the sheet in the engineering environment.In order to solve the above problems,the drawing and bulging performance test method and equipment of the sheet were mainly studied.The sheet stamping forming test method based on the engineering environment was obtained and the drawing and bulging performance tests were carried out.The main research contents are as follows:Firstly,the parts commonly used to study the drawing and bulging properties were selected as the object for theoretical analysis,combined with the forming characteristics of the actual parts to select the appropriate test part and performance evaluation indicator.The sheet cracking failure judgment method combined with image-displacement was innovatively proposed to judge the end point of test,based on this,a test method for sheet drawing and bulging performance under the engineering environment was proposed.Secondly,based on the rational design of the mold size,a common mode scheme for drawing and bulging test was proposed,which greatly simplified the test process.In order to accurately judge the cracking moment and measure the extreme height of drawing and bulging under high-speed stamping conditions,optical sensing equipment and displacement sensing devices were installed in the traditional mold structure.In order to ensure the feasibility of the test method and device,the bulging test was carried out.The results show that the test methods and equipment described in this article can successfully judge the failure time and position of the sheets,and accurately obtain the bulging limit performance of the sheets under engineering environment.Thirdly,the self-developed test equipment was used to analyze and compare the commonly used sheets of automobiles,the variation law of forming limit performance and initial cracking position of the sheets under engineering environment were obtained.Then used the theoretical and experimental results to analyze the engineering application of the three typical links in the automotive product development process in order to grasp the engineering application scenarios of the research results more intuitively.The test method and test device proposed in this article have the characteristics of high precision and high efficiency,and realize the accurate acquisition of the limit forming performance under engineering environment.which can provide a more scientific test method for the follow-up study of drawing and bulging limit performance.The sheet cracking failure judgment method combined with image-displacement can also provide new ideas for other tests,both have broad application prospects and reference value.