CURVATURE ANALYSIS AND DUCTILITY CALCULATION OF FLANGED SHEAR WALLS

Based on the moment-curvature analysis of flanged shear walls with asymmetric cross-sections, the sectional yield curvature and ultimate curvature when the flange is in tension and in compression are calculated. By analyzing the influence of the axial compression ratio, longitudinal reinforcement ratio, web distributed vertical reinforcement ratio, flange width to web height ratio, concrete strength, stirrup characteristic value and web height to thickness ratio on the sectional curvatures, the variation of sectional curvatures with each influential factor is elaborated in detail combined with the change in the depth of the compressive zone. Through a regression analysis of the calculation results under 4941 conditions, simplified formulas for calculating the yield curvature and ultimate curvature of flanged shear walls are established. Formulas for estimating the curvature ductility and displacement ductility are also derived. The accuracy of the calculation formulas is verified by the comparison with the experimental results. The proposed formulas not only distinguish the cases with the flange in tension and the cases with the flange in compression, but also consider the effects of key factors affecting the sectional curvatures. They provide references for the deformation capacity calculation and the displacement-based seismic design of flanged shear walls.