Effects of a strain rate sensitive material on the optimization of an hydroforming process

The hydroforming process of a T-tube is simulated with the finite element code ABAQUS. The influence of the internal pressure and the axial displacement levels on the final tube quality is evaluated through a”process diagram”. Due to the strain rate range observed during the process, the strain rate sensitivity of the material is considered for the determination of the forming limit curves and for simulation of the process. Theoretical and numerical evaluation of the forming limit curves shows that formability increase with the strain rate sensitivity coefficient m. The determination of the process diagram for a higher value of memphasizes that the forming zone (tube with zero defect) significantly grows. The optimization of hydroforming process is very sensitive to forming limit curves identification and the effects of strain rate on formability must be accurately quantified.