Coupled thermal-mechanical FEM analysis of power spinning of titanium alloy thin-walled shell

The hot power spinning of titanium alloy thin-walled shell is a complex metal forming process. The establishment of a reasonable finite element method(FEM) model is the key to obtaining informaltion such as the temperature field, stress and strain fields in the forming process. The establishment of a reasonable FEM model also can supply a reasonable guide for revealing deformation mechanism, choosing processing parameters and improving the forming quality. Based on applying an appropriate temperature boundry condition to simulating external heat source and considering various heating effects, a 3D elastic-plastic FEM model for hot spinning of titanium alloy thin-walled shell is established by using the dynamic, temp-disp, explicit module of the FEM software ABAQUS. The distribution features of temperature field, stress and strain fields on the hot power spinning process of TA15 titanium alloy thin-walled shell are analyzed, the influence law of roller working radius on the gap between blank and mandrel is also researched. The results are shown as follows: The influence of contact heat exchange and friction heat can cause a great temperature gradient along the thickness direction of deforming zone, thereby resulting in remarkable inhomogeneous deformation; The maximum equivalent plastic stress, which lies in the round zone in the beginning and the zone contacting with rollers at later stage, stress concentration occurs on the outside of blank at later stage; The gap between blank and mandrel increases as near the oral part of workpiece; With the decrease of roller working radius, the gap characteristics are better.