Simulation Analysis Of Surface Low Of Automobile Panel

Auto body panels stamping is a widely used plastic forming technology.Finite element numerical simulation technology has also been widely applied on the basis of this.However,with the gradual use of the thinner high strength steel plate and aluminum plate,the surface low of the body cover gradually increase,and the limitations of the finite element simulation technology have begun to appear.On the basis of previous experimental research,this paper further explores some key technologies of finite element simulation in order to predict the size of surface low and the direction of springback through finite element simulation,and to compensate the springback on the model surface on this basis,in order to apply the finite element simulation technology to better application.To guide actual production.First of all,the surface low feature test and test results are briefly introduced.The key technologies in the finite element simulation,such as the finite element solution algorithm,the material model,the element type and the finite element mesh division are discussed,and the evaluation criteria for the shape of the feature parts and the direction and size of the springback are also introduced.Based on the analysis of the characteristic parts and the dies,a numerical simulation model and a springback algorithm for feature stamping are established based on DYNAFORM.Secondly,through numerical simulation,the influence of the initial mesh size of the blank and the tool body,the type of the element,the control mode of the blank holder,the size of the blank holder force and the number of the thick integral point on the result of the forming and springback of the feature parts is studied,and the accuracy of the springback direction is observed.The results indicate that the initial mesh size of the blank and the tool has a great influence on the forming and springback results,the proper size of the initial mesh can get the correct size and direction of springback;the forming simulation result is the foundation of the springback,and the result is obtained by the simulation of the 2 BT element and the 16 full integration unit of the springback mining.The most ideal,manual offset thick gap 1.1t,the use of fixed edge force size of the edge ring control method and the actual test conditions are in line with the actual conditions,the thickness of the number of points on the simulation result is not significant,springback simulation should increase the number of integration points,but more than 9 integral points for the precision of the springback is not too big promotion,not recommended.Finally,based on the above conclusions,we explore the influence of material and surface factors on surface defects.At the same time,the theory of the influence of air on the experimental results is put forward,and the general discussion and simulation analysis have not been obtained,but it provides a reference for the design of stamping die.Under the condition that the size and direction of the surface defect are more accurate,the resilience compensation function of the software itself is used to compensate the die face two times,and the die surface after the compensation is simulated again,and the ideal results are obtained.