A study of cold roll forming technology and peak strain behavior of asymmetric corrugated channels

The peak strain (PS) of sheet metal highly affects the process design and the quality of roll formed product. Different from the traditional roll forming technology (RFT) that all the cross section contours of the product are rolled simultaneously, a symmetric RFT is developed with respect to the corrugated channels to avoid defects like tearing, twist, and redundant deformations. The behaviors of their peak strains are subsequently simulated with finite element (FE), and the effects of three factors of the rolling speed, friction coefficient, and the bending angle of roll are analyzed, respectively. Finally, both the rationality of RFT and the accuracy of final rolled product are verified by experiments. Results show that the maximum peak strains are also distinguished for their different channel width, with respect to two symmetrical channels forming simultaneously even under the same bending angle and the pressure of roll. The maximum PS of the narrow channel is significantly larger than that of the wide, and the closer to the middle channel, the greater the PS of the narrow channel, which is on the right of bending angle of the trough. Moreover, the maximum PS is mainly influenced by the friction coefficient and bending angle of the first forming pass. This can provide a reference for other design of RFT and rolled forming quality improvement of the corrugated channels.