R Azizi Tafti - Department of Mechanical Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran
H Moslemi Naeini - Department of Mechanical Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran
M Salmani Tehrani - Faculty of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
M Farzi - Faculty of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran

Excessive longitudinal strain is the main reason of occurring buckling defect at strip edge. A theoretical relation was developed for longitudinal total strain based on the method proposed by Bhattacharyya for roll forming of a channel section. Theoretical results showed that forming angle, flange length, strip thickness and distance from the bend line are the most effective parameters on longitudinal strain and the effect of later is more than the others. The process was simulated three dimensionally by Abaqus software to improve the buckling prediction and to consider yield strength of strip. Simulation results showed that the forming angle, flange length and strip thickness are the most effective parameters on edge buckling respectively. These conclusions were in good agreement with theoretical results. According to the theoretical and numerical results, by increasing the forming angle and flange length and decreasing the strip thickness, buckling probability increases. Low yield strength strips are prone of wavy large amplitude buckling while higher yield strengths may lead to buckles with less wave numbers.

Channel section; Cold roll forming; Edge buckling; Longitudinal total strain; Finite element simulation