Springback of Sheet Metal Bent to Small Radius/Thickness Ratios

In a previous SAE paper (940938) Huang and Gerdeen showed that there was very little experimental data available for springback of small radius-to-thickness bends, in the range R/t < 10, and that the data showed larger spring back than that predicted by any known theory. Due to this lack of data, additional experiments have been conducted on three steels: a F50, an IF, and an AKDQ steel. Results of these experiments are reported in this paper.