Seismic tests and numerical investigation of blind-bolted moment CFST frames infilled with thin-walled SPSWs

Abstract

This paper aims to investigate the seismic response of blind-bolted moment concrete-filled steel tubular (CFST) frames infilled with thin-walled steel plate shear walls (SPSWs). Tests of two-storey blind-bolted circular or square CFST frames with thin-walled SPSWs subjected to horizontal low-cyclic loading were performed. Macroscopic finite element (FE) models of the specimens were primarily established by fibre beam-column elements, zero-length springs, and truss elements. The numerical simulation results were verified by the experimental data. A parametric analysis was conducted to analyse the influence of the axial load level, material strength, and height-thickness ratio of the steel plate etc. on the hysteresis behaviour and energy dissipation of blind-bolted moment CFST frames with thin-walled SPSWs. In addition, the mechanics of the semi-rigid frame with SPSWs were compared with the pinned and rigid frames with SPSWs using mechanical analysis model and FE model. The experimental and analytical results show that the blind-bolted moment CFST frames with SPSWs connected to the beams only exhibit preferable hysteretic response, ductility and energy dissipation. The peak strength, initial stiffness and energy dissipation of blind-bolted moment CFST frames infilled with thin-walled SPSWs can be significantly affected by the axial load level as well as the steel plates' yield strength, height-thickness ratio, aspect ratio, and connection type.