Daejeon: The Korea Advanced Institute of Science and Technology
limit. Two sets of tools with different dimensions were designed for experiments to verify the reliability of the program. By using the designed tools for re-penetration process, this paper studied the effect of the direct penetration and re-penetration on the workpiece. Besides, this paper also discussed the comparison of experiments and numerical analysis between penetration and re-penetration processes. According to the comparison between simulation and experiment, the punch load of re-penetration was less than the punch load of direct penetration. The maximum punch load increased remarkably upon decreasing the profile radius of cylindrical punch and the initial diameter of the inner hole of blank. Moreover, the re-penetration had better formability than the direct penetration in the same condition. The forming limit ratio of the re-penetration process was improved from 2.70 to 2.97. The simulation results showed good agreement with the experiments.
Proceedings of 10th International Conference on Advances in Materials and Processing Technologies (AMPT2007), 5p.