Seismic performance of the WCFTC-beams joint with high-strength double-side plates

Abstract

This research presents a novel joint design for wall-type concrete filled steel tube (WCFTC) beams, integrated with high-strength double-side plates, resolving the problem of traditional side plate extending from the wall and interfering with wall panel installation. The study synthesizes a reliable finite element (FE) model corroborated by previous experimental analyses, enabling a detailed parametric study on the dimensions of the side plates. Comprehensive analysis assessed the impact of steel plate thickness and material strength on the joint's seismic properties, uncovering that the innovative joint design reduces steel usage while maintaining load capacity. Subsequent full-scale testing of prototypes under cyclic loading revealed the failure modes and hysteresis responses, which exhibited notable energy dissipation reflected in ductility coefficients exceeding 3.0. The study also identifies the plastic hinge location to be at a distance ranging from 1.0 to 1.5 times the beam's height from the column's edge, validating the efficacy of the joint design categorized as full-strength or rigid. Furthermore, comparative assessments of Q690D and Q460C steel plates indicated similar performance, suggesting a flexibility in high-strength material choice without loss of joint integrity. The culmination of the study is the proposal of a clear and actionable design method, predicated on the synthesized findings, offering a pragmatic reference for designers and engineers in the field. This method aims to streamline the adoption of this advanced joint construction for enhanced seismic resilience in structural applications.