RESEARCH ON NONLINEAR PINCHING HYSTERESIS MODEL OF SHEATHED COLD-FORMED THIN-WALLED STEEL STUD WALLS

In order to study the hysteresis performance of sheathed cold-formed thin-walled steel stud walls, four full-scale 3m×2.4m (height by width) specimens, with different configurations, were tested under cyclic loading. According to the hysteresis rule achieved from experiments, the three-segment nonlinear pinching hysteresis model, capable of representing specimens’ hystersis charactersitcs of nonlinear, pinching, strength and stiffness deteroiration, is established by using Richard-Abbott curve. And model parameters of specimens were estimated by Origin 8.0 software. The experimenal investigation indicates that the experienced maximum displacement is the key factor that influenes the hysteresis curve, and the ascending or descending curve of typical pinching hysteresis loop can be divided into three segments, where each one has monotone stiffness change. The hysteresis curves, simulated by the three-segment nonlinear pinching hysteresis model, agree well with experimental hysteresis curves, showing the proposed model can represent the stud walls’ hysteretsis behavior comprehensively. Moreover, with intuitive mathematical expression, parameters of the model have clear physical meanings and they are easy to estimate.