Simulation of Shape Distortions During Flat Bottom Raising Process with Titanium Alloy Sheet Based on ADINA

摘要

Raising processes of titanium alloy sheets TC1M 8 1.45 were simulated based on ADINA FEA software. The shape distortions induced by plastic anisotropy during forming and springback processes were described. A series of forming tests were conducted for the comparison of simulation prediction and test measurements. Reasonable agreement was obtained between the predicted and measured profiles of formed parts, It shows that the ADINA software is suitable for the analysis of the forming and springback processes of anisotropic titanium alloy sheets. Two sorts of shape distortion phenomena exhibit in the raised workpieces fabricated in room temperature after springback or elastic recovery process: Firstly, the bottom of the flange in the specimen distorts to be a wavy surface and not a plane. There two high points and two low points, and the high points locate in the flange periphery along the transverse direction(TD), and the low points locate in the periphery along the rolling direction(RD); Secondly, the top surface of the raising specimen distorts to be a wavy surface too, and the distortion shape is similar to that in the flange. During thermoforming at 600℃, the elastic recovery can be suppressed effectively and the shape distortion resulted from springback processes can be eliminated, but the anisotropy characteristics of the titanium alloy sheets can not be changed, so forming at high temperature can not solve all the shape distortion problems except the distortion occurred for the reason of springback, unhomogeneous deformation in thickness still exists.