Influence of internal pressure on hydroforming of double handles crankshaft

The hydroforming process of a double handles crankshaft with the biggest expansion ratio up to 54% is studied by means of simulation and experiment in this paper. The effects of loading paths during hydroforming process on the failure modes are analyzed. The simulation results show that the part can be formed successfully with the feeding pressure selected in the range from 65 to 75 MPa. A successful crankshaft component can be manufactured in the experiment as the internal pressure is 70 MPa. Folding back occurs as the internal pressure <65 MPa and bursting occurs as the internal pressure >75 MPa. The most serious thinning occurs in the top of crankshaft handle. The maximum thickness appears in the area of the opposite to crankshaft handle. The maximum of thinning rate by the simulation is about 11%, which is close to 10% that is obtained in experiment.