Effective stiffness of steel plate-concrete composite shear wall structures under normal status

摘要

Shear walls are the primary lateral-load carrying elements in tall buildings. The steel plate-concrete composite shear walls have good advantage in mechanical properties for the combined effect of two kinds of materials. It composes two steel plates with studs inside, side columns made of steel tube and an infill of concrete. This paper focuses on the effective stiffness and the ultimate loading capacity of the composite shear walls. Many design practices currently deal with shear stiffness by employing a stiffness reduction factor. In this paper however, a model called PCTM (Plane Combination Truss Model) is built for effective shear stiffness of the composite wall based on the theory of fixed angle truss model. The formula for calculating the effective shear stiffness of the composite shear wall is derived based on the model. A numerical model for elasto-plastic analysis of the composite wall is built to find the key factors for the effective flexural stiffness subjected to axial force and bending moment, the simplified design formulae for which are obtained based on the parameter analysis. The effective stiffness is obtained by combining the flexural stiffness and the shear stiffness. The predictions of effective stiffness correlates well with experimental results of a series of composite shear wall specimens.