| The rapid development of the automobile industry has made great contributions to the national economy.Under the demand of the market,the car is continuously updated,and the automobile panel is an important part of the car.Its manufacturing technology restricts the development of new models.The structure of the automobile panel is complex and the law of deformation is difficult to grasp.The quality is determined by the manufacturing tool-the stamping die.However,traditional stamping die need to pass a large number of test models and repeated molds to produce qualified products,which is wasting a lot of resources,and having a long production cycle.With the development and widespread application of computer simulation technology,the traditional manufacturing process was improved.Before the manufacturing of the mold,the software was used to design the process and simulate the forming results to predict and improve the forming defects in advance,which greatly saved the manufacturing cost and shortened the production cycle.The formability of automobile wheel inner side panel is studied and numerical analysis is carried out in this thesis.Through the optimization of process parameters,the defects of cracking,wrinkling and springback in the forming process are solved,and the forming performance of the inner plate of the car wheel side is improved.The content of this paper is as follows:(1)A DC04 steel plate with a thickness of 2mm was used as a research material,and a uniaxial tensile test was conducted at different tensile speeds to obtain the rheological curves of the sheet material at different rates,and the mechanical properties parameters were obtained.The results show that DC04 material has good plasticity and high elongation,which is suitable for parts with deeper depths such as the inner plate of the car wheel.(2)The formability of the wheel inner side panel is analyzed and numerical simulation is carried out in this paper.The effects of blank shape,process replenishment,blank holder force and drawbead coefficient on drawing performance are studied in this paper.The results show that the rectangular material is more effective than the shapeless ones;the modified supplementary surface increases the sheet flow resistance and effectively improves the wrinkle defect;the modified process supplement surface increases the sheet flow resistance and effectively improves the wrinkle defect;with the increase of the blank holder force,the wrinkling area gradually improved;the drawstring coefficient increased,and the forming performance was improved,and the coefficient was too large to cause cracks.(3)Orthogonal test is used to optimize the blank holder force,the clearance between the punch and the die,the friction coefficient and the the strength of drawing.The influence of four process parameters on the sheet metal forming is summarized.The maximum thickness and the minimum thickness are used as indexes to judge whether the part is wrinkled or cracked.The test results show that the order of the factors affecting the maximum thickness is the friction coefficient>blank holder force>tensile strength>gap between punch and die,and the influence on the minimum thickness is the strength of he strength of drawing> gap between punch and die>friction coefficient>blank holder force.Through further analysis,the optimal forming plan is determined.(4)The iterative method and the direct method are used for the whole wheel compensation for the car wheel side inner plate.The results show that the iterative compensation result is ideal and meets the requirements of the parts.The direct compensation result has failed to meet the requirements of the parts.It is important to inspect the iterative compensation result to obtain qualified parts and to guide the improvement of the production process. |
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