Mechanism of Cut End Deformation of Hat Shape Channel Steel by Roll Forming

The hat-channel steel is channel with a bottom horizontal web and two vertical (web) with outward flange fabricated by roll forming. Roll formed hat channel will flair in (closing) at front end and flair out (opening) at tail end when cut off into component and this is called cut end deformation. The mechanism of pipe end deformation after cut-off hat channel in length was investigated by experimentation and finite element (FE) analysis. Residual shear stress in the longitudinal direction and in-plane shear stress at the edge become owning to outer and inner elements. The upper part of flange will have opposite reverse bending deformation with the lower part of flange. Opposite direction of residual twisting moment occurs at the upper part and lower part of flange. These stress and moments offset each other making the cut end deformation small at cutting edge.