Elasto-Plastic Seismic Shear Distributions of Frame-Wall Structures

In this study, theoretical and numerical methods were used to research seismic shear distributions of frame-shear wall structures under elasto-plastic conditions. The shear distributions of frame-shear walls were analyzed based on a simplified elasto-plastic analysis model of flexural shear. Based on a preliminary project, three groups of 2D models with different stiffness eigenvalues were designed and used to compare the shear distributions of whole structures and frames. The characteristics of the shear distributions of structures and frames and the development of plastic hinges were analyzed, and the rationality of shear adjustment based on Chinese standards was discussed from the perspectives of structural design, seismic performance and collapse resistance. The results revealed obvious differences between shear distributions of structures caused by strong vs. frequent earthquakes. For strong earthquakes, the shear distributions tended to be evenly distributed with respect to height, while the shear force of the bottom story was significantly larger than that of the upper stories. This was mainly caused by the redistribution of plastic internal forces due to the development of plastic hinges. The shear adjustment of the frame usually affected the reinforcement in the beams rather than in the columns, which contradicted the design concept of strong columns – weak beams. Additionally, shear adjustment had little effect on the seismic performance and collapse resistance of structures. This paper suggests that by ensuring the ability of strong columns, weak beams and plastic hinges to rotate, shear force adjustment can be prevented.