Influence of punch shape on rollover of hydropiercing

To investigate the influence of punch shape on collapse of hydropiercing, seven different shapes of the punch were designed for the hydropiercing experiment, and the influence was analyzed. The results show that, with the increasing of the punch face angle, the collapse depth decreases, and with the increasing of the punch round, the collapse depth increases. Increasing the internal pressure can reduce the collapse depth. The influence of different punch on collapse was dissimilar. The collapse depth for the punch with sloping end face was smaller, while that for the punch with fillet was larger.