Experimental and numerical study of required torque in the cold roll forming of symmetrical channel sections

Abstract

Because of the high complexity of the cold roll forming process, an accurate estimate of the torque required at each stand is not possible and, in many cases, the designs of cold roll forming lines are based on trial and error. This study experimentally investigated the fold angle increment at each stand, internal distance between the stands, strip thickness, flange width, and channel corner radius to determine their effects on the required torque. Also, using finite element simulation, the effect of plastic strain distributions in flange and bend zones on the required torque was studied. Then, a regression method was used to categorize each studied variable based on its effect on the required torque to produce a channel section in the roll forming process. The microstructure of the bend zone was also studied to see its relation with strain distribution. Experimental results indicate that the strip thickness, fold angle increment, and flange width have the greatest impacts on the required torque, in order of decreasing impact. Numerical results indicate that, unlike the flange width, any variable which increases the longitudinal edge strain will increase the required torque. The findings are expected to help designers and researchers to optimize the torque required for the roll forming lines. This can consequently lead to an optimized energy consumption.