Cyclic behaviour, deformability and rigidity of stiffened steel shear panels

Shear panels play an important role in improving the seismic behaviour of structures. They generally occur as thin steel plate shear walls (TSPSW) or shear panels created within the web of link beams in eccentrically braced frame (EBF) structures. The post-buckling capacity, deformability and energy dissipation of shear panels are now widely accepted by structural engineers and has resulted in more economical designs. Comparing the behaviour of unstiffened panels with that of heavily stiffened panels shows that unstiffened panels provide a more ductile response while heavily stiffened panels have a wider yield area, which in turn results in higher energy dissipation. Considering these two extreme cases, simultaneous maximum ductility and energy dissipation response cannot be expected. In this numerical research the effect of stiffening upon the ultimate strength of shear panels is investigated. Then, the cyclic behaviour of stiffened and unstiffened shear panels is studied. Finally, with regard to the smaller areas contained within the hysteretic loops of unstiffened panels (due to their pinching records), the optimal stiffening needed to provide both the desirable energy dissipation and ductility is investigated.