Analyses on mechanical performance of innovative composite shear wall systems

The steel-concrete composite shear wall system studied herein consists of a steel boundary frame, a steel infill wall with a reinforced concrete wall attached to one side by bolts. In the traditional system the reinforced concrete wall is in direct contact with the boundary steel frame, while in the innovative system there is a gap in between to prevent contact when lateral displacement is small. ABAQUS was used to establish refined finite element models of these two types of composite shear wall systems, and analyses were conducted to reveal the whole process of the lateral force resisting mechanism and the wall-frame interaction. Parametric studies were conducted on the influence of height-to-thickness ratio of the infill wall on the overall capacity, lateral stiffness, shear force distribution between wall and frame of the composite shear walls. Results show that the concrete wall can effectively prohibit elastic buckling of the steel wall; shear yielding is the main lateral load resisting mechanism of the steel wall; and the additional bending moment on the boundary column is obviously reduced as compared to steel shear walls.Bearing capacity and lateral stiffness of the traditional composite shear wall are increased by 25% and 10% respectively compared to steel plate shear wall. The concrete wall carries nearly 30% of the total lateral load, which may cause more severe damage to it in later stages. Bearing capacity and lateral stiffness of the innovative composite shear wall are increased by 10% and 5% respectively compared to steel plate shear wall, with the concrete wall carrying the minimum lateral load. As height-to-thickness ratio of the steel plate is decreased, the bearing capacity and the lateral stiffness of the composite shear wall systems are increased, while the difference between the two systems is reduced, and the portion of lateral load resisted by the steel wall is increased. When the steel plate is too thick, the bottom portion of the frame may yield prematurely.