Experimental investigation of axial supplement effects on three-stepped shaft hydroforming

The influence of axial supplements on three-stepped hollow shaft hydroforming was investigated experimentally to explore the effect of processing parameters on tube hydroforming. A general formula was developed to estimate the axial supplement. Variations of hydroformed shaft properties were analyzed for axial supplements from 80% to 120% of the theoretical supplement. The experimental results show that for axial supplements less than 90% or more than 110% of the theoretical supplement, the shaft tends to buckle or wrinkle with large changes in the shaft thickness and that the 90-mm diameter step is most sensitive to the supplement reduction and is most likely to buckle. The results also show that the axial supplement greatly influences the transition region between the supplement region and the deformation region.