RESEARCH ON ANALYTICAL MODELS FOR UNSTIFFENED STEEL PLATE SHEAR WALLS

One of the analytical models, namely the Strip Model(SM) developed by Thorburn in 1983, was recommended to analyze unstiffened steel plate shear walls (USPSW) in CAN/CSA S16-01 and AISC. Some results showed that the SM tended to underestimate both the ultimate capacity and the initial stiffness. In order to obtain a more accurate prediction of the overall behavior of USPSW, the SM was refined and renamed Modified Strip Model (MSM) by Alberta University in 2005. However, the applicable region for neither SM nor MSM was addressed regarding the slenderness ratio of the wall. The results obtained in this paper indicate neither the SM nor the MSM can be regarded as a reasonable model since neither of them is able to well describe the behavior of the USPSW with arbitrarily varying slenderness ratio. A new analytical model, namely the Unified Strip Model (USM) considering the combination of the pure shear and pure tension fields, is proposed in this paper, and the ratios of true shear and tension field action vary in accordance to the thickness of the wall. It is then verified that the USM gives a better prediction of overall behavior, including the initial stiffness, elastic frame force and hysteresis loops for USPSW than other models, meanwhile the vagueness of applicable scopes which exists in the other models is overcame.