Finite Element Simulation Of Thin-walled Shaped Tube Forming Process And Pilot Study

Based on the Cooperative project of Taiyuan university of science and technology and Citic heavy industries co.LTD.—Research on the forming technology for the pre and post segment special-shaped ring of the missile, and equipment condition of the compony ,this paper makes the technological process for the pre and post segment special-shaped ring and designs the related molds to ensure the manufacture of products successfully.The special-shaped ring that we study has greater particularities:special material,a special steel that has the great deformation resistance at a high temperature;the shape has a small taper;the bottom has a contracting;the product is big and the wall-thickness is thin.Doing the technological research to the product that has a special use has the important significance.Based on the equipment condition,we analyze the product carefully and see the production technology of the previous similar cup shell,and determine the forming technology preliminarily: hot back-extrusion—punching recess—rolling.The forming technology uses not only the extrusion that has a long development history and a widespread use but also the special forging forming technology rolling.Because it combines a series of different technologies,the making of the technological method is special.According to the technological process,this paper designs the related hot back-extrusion die, punching recess die and rolling die,then we use the finite element software Deform to simulate the whole forming process of the product.The problems of the product end surface is unevenness and the stress of the combined die is large appear during the process of the back-extrusion.This paper solves the two problems successfully through adding the pre-pressing caverna process and optimizing the combined die. The finite element software Deform simulates the following punching recess and rolling process and the shape size ,stress and strain and so on meet the demands of the final product.Based on the back-extrusion die that we design,this paper uses Pb instead of the actual steel to do the 1:5 subscale test at room temperature.The test divides into two groups:one is the direct back-extrusion and another is the pre-pressing caverna - back-extrusion.The direct back-extrusion process has the defect that the end surface is unevenness, but the pre-pressing caverna - back-extrusion process solves the problem effectively.Therefore , the pre-pressing caverna—hot back-extrusion—punching recess—rolling technological process can make the pre and post segment special-shaped ring successfully,and it has an important guiding significance to the similar special-shaped ring.