# Study on Lateral-Load Resisting Mechanism and Capacities of Steel Frame Infilled with Composite Plate Shear Wall Under Cyclic Loading

## TL;DR

This study examines how steel frames and composite plate shear walls work together to resist lateral loads under cyclic loading, aiming to improve seismic design.

## Contribution

The paper proposes new formulas for lateral stiffness and strength of SF-CPSW based on experimental and analytical findings.

## Key findings

- CPSW and boundary SF interactions cause significant normal stresses at CPSW corners, reducing steel web shear strength.
- Concrete encasements and boundary SF enhance stiffness and ductility of the SF-CPSW system.
- Formulas for lateral stiffness and strength of SF-CPSW were developed for seismic design.

## Abstract

Steel frame infilled with composite plate shear wall (SF-CPSW) is an effective structure for lateral-load resisting. In the structural design, the vertical loads are primarily carried by the boundary SF, while the horizontal loads are expected to be totally carried by CPSW. CPSW incorporates the steel web and the concrete encasements. For the CPSW bays, the boundary SF also inevitably withstands the lateral-loads due to the coordinated deformations between boundary SF and CPSW. The available researches, however, have not given a certain shear force assignment between the boundary SF and CPSW. Furthermore, their interactions under the cyclic lateral-loading are unclear. This paper conducted a study on the load-resisting mechanism of SF-CPSW by a structural model test and finite element analyses. The deformation pattern, failure mode, internal forces, and interactions of structural members were investigated. The effects of steel web and concrete thicknesses, cross-sections of boundary SF, and axial compression ratio on the lateral-load resistance of SF-CPSW were assessed. The results indicated that the interactions of CPSW and boundary SF caused significant normal stresses at the corners of CPSW, reducing the shear strength of steel web. However, the concrete encasements and boundary SF compensate it and mutually improved the stiffness and ductility. According to the analysis results, the formulas of the lateral stiffness and strengths of SF-CPSW were proposed for its seismic design.