Deformations in Cold-bent HSS Members

The purpose of this investigation is to predict the relation between the radius of bend and the distortion of Hollow Structural Section (HSS) members. An experimental program was carried out using twenty-seven different profiles of HSS members. The pyramid-type, three-roller bending machine was used as the method of cold-bending. The cross-section distortion is defined by two parameters that describe the permanent deformations in the flange and web of the crosssection. Multiple regression analysis was used to obtain a relation between each of these parameters, the cross section properties and the radius of bend. The effect of the resulting distortion on the moment of inertia of the HSS member is also studied. A parametric study is undertaken to demonstrate the influence of the change in the cross-section dimensions on the permanent distortion.