Study On Sheet Springback Under Servo Stamping

In recent years,the automotive sector has been steadily moving towards energy conservation and intelligence,and it is bound to promote the development of automotive manufacturing to be lightweight and intelligent.Servo presses have followed the trend.The servo press can realize the characteristics of flexible and precise control of the slider movement,and has the requirements of intelligent and flexible press processing.After the sheet is bent and formed,there is residual stress and elastic recovery,so the springback is an inevitable phenomenon after the sheet material loses external force in bending forming.The results of springback and assembly stamping precision,forming quality and geometric reliability and other properties.There are many reasons for the impact of springback,and it is difficult to give an accurate theoretical springback value.This paper uses the orthogonal test method and finite element simulation technology to study the springback of U-shaped parts and to reduce the stamping pressure by optimizing the forming process parameters.This paper mainly includes the following research work:(1)In this paper,the most common two kinds of sheet-low carbon steel Q195 steel and aluminum alloy AL6061,are the research object.First of all,in accordance with the national standard,we design and process the standard samples and U-shaped parts springback mold.In this paper,the springback problem of U-shaped parts is studied.Firstly,the theoretical principle of the bending deformation stage and the main factors affecting springback are analyzed,and the relationship between creep and stress relaxation is explained.Creep experiments are designed to study the relationship between stress relaxation and the reduction of springback.Creep tests were performed to investigate the performance of the material itself through uniaxial tensile tests at different speeds,stretching,and multiple positioning and reloading.(2)To intensive researching Orthogonal test,first of all,select the process parameters to be examined,and use the springback angle of U-shaped parts as the assessment criteria.Through orthogonal tests,we can obtain the U-shaped parts' springback data at different ram speeds,intermittent times,intermittent times,and die corner radius.By this,we can analyze the influence of different process parameters on the primary and secondary impacts,and get a set of optimal forming process plans was obtained.(3)Simulate and analyze the bending springback of U-shaped parts through Dynaform software.Analyze the relationship between the stamping speed,the corner radius of the die,and the springback amount of U-shaped parts.Through the simulation of the U-shaped parts,we verify the accuracy of orthogonal test results,which provides a reference for actual production process parameters.