The 14th World Conference on Earthquake Engineering

This paper presents a computational study assessing the seismic response of rectangular concrete-filled steel tube (RCFT) members and frames to develop a reliability-based performance-based design methodology. A new analysis formulation was derived based on a mixed-finite element approach allowing geometrically and materially nonlinear analysis of RCFT frames under seismic and non-seismic loadings. The mechanism of load transfer and composite interactions between the steel tube and the concrete core were accounted for through calibrating the formulations based on a comprehensive range of experimental results in the literature. The formulation was then used to study the progression of damage within a series of RCFT frames to facilitate the development of performance-based design provisions for composite structures. Multiple earthquake records were selected representing ground motions with far-field characteristics, and the nonlinear dynamic seismic response characteristics of the frames were documented in terms of structural parameters describing the damaged state of the RCFT frames.