Modelling hysteretic behaviour of cold-formed steel wall panels

Cold-formed steel shear wall panel (CFSSWP) is a main lateral load resisting system in the CFS wall panel building system. It consists of CFS framing members attached to sheathing with screw connections. The hysteretic behaviour of a properly designed CFSSWP is dictated essentially by the hysteretic behaviour of the screws connecting the sheathing to the CFS framing. A numerical model of the hysteretic behaviour of such panels is necessary to study the system behaviour under various earthquake loading. In this paper, Bouc–Wen–Baber–Noori (BWBN) model is used to capture the deteriorating behaviour, such as the strength and stiffness degradation with severe pinching, observed in the screw connections between the CFS framing members and sheathing, as well as the full wall panels under cyclic loading. The system identification technique based on Nelder and Mead’s simplex algorithm is used to identify the unknown parameters of the model. The representation of the constitutive relationship, both under static and cyclic loading of the screw connections and the wall panel sub-system, is demonstrated using the BWBN model.