Simulation Analysis And Application Of Hot Forming Of High Strength Sheet Metal

In recent years,China’s automobile industry has made rapid development and great progress,and the production and sales of passenger cars of our own brands have made great progress.At the same time,although our automobile R &D strength has been strengthened,there is still room for progress compared with foreign counterparts.Consumers pay attention to safety and fuel economy,so the industry demand for lightweight and high safety performance is more and more strong.At present,there are many ways to improve the lightweight and safety performance of automobiles.Generally speaking,there are the use of new structures,the use of new lightweight materials instead of some traditional materials,and the exploration of new manufacturing processes.There are a large number of stamping parts on the car body,and this paper is to study the application of thermoforming technology in the car.Thermoforming technology is a new stamping technology of high strength steel plate.This technology solves the contradiction between strength and plasticity of high strength steel.The traditional cold stamping technology has an inverse ratio between the forming performance of high-strength steel(generally tensile strength is about400-450 MPa)and its physical performance,so it is difficult to control the springback,so it needs several processes to complete.However,the tensile strength of hot formed steel can be increased to 1300-1600 mpa,which is 3-4 times of that of ordinary steel.Hot formed steel is widely used in some key parts of BIW,such as a,B,C pillars,anti-collision beams of doors,strengthening plates of channels in cars and other key safety parts.It can not only improve the safety of vehicle collision,but also reduce the weight of the vehicle.In this paper,based on the domestic and foreign research status,we select the middle channel stiffener of a certain vehicle as the research object,and fully study the basic theory of hot stamping technology.Then,based on the CAE computer aided design simulation software,the simulation model is established.Combined with the characteristics of the middle channel stiffener,the manufacturing process is determined,and the simulation of "heating single dynamic drawing springback calculation cooling" is carried out.Then,this paper studies the influence of many process parameters,such as initial temperature of sheet metal,stamping speed,friction coefficient,holding time and so on.Finally,the development of the die for the middle channel stiffener is verified.In this paper,the research work is carried out from material,structure,simulation,process,mold,precision prediction and control,test and other dimensions.In this paper,the mechanical action and heat exchange of sheet metal,die and surrounding parts in the process of hot forming are studied,the process route of hot forming is studied,and the simulation work is carried out by means of CAE simulation,and the influence of various process parameters including initial temperature of sheet metal,stamping speed,friction coefficient and holding time on the hot forming of the middle channel reinforced plate is studied by using the control variable method.In this paper,the application of thermoforming technology in the middle channel reinforcing plate is explored in the aspects of the structural design and process development of thermoforming die,the arrangement of cooling system,the use of thermoforming steel,the division and distribution principle of die inserts,etc.To sum up,the combination of theory and practice,simulation and experiment,and the research of thermoforming technology can guide designers to design thermoforming parts and dies quickly,and ensure the accuracy and performance of parts.