Low-rise steel moment-resisting frames with novel re-centering beam-to-column connections: connection modelling and system performance evaluation

Abstract

This research focused on a new type of re-centering beam-to-column connection for use in low-rise steel moment-resisting frames (MRFs). A new material model was first developed and validated to accurately, conveniently, and efficiently simulate the nonlinear behavior of the critical components of the connection. To demonstrate its potential, a representative low-rise MRF previously investigated was revisited and re-designed with the considered re-centering connection. Specifically, the re-centering beam-to-column connections in the re-designed system are controlled to have the same flexural resistances as the corresponding ones in the original system under the connection rotation angle of 0.025 rad. Computer simulations were conducted to compare different aspects the original and re-designed systems under the design basis earthquake level excitations. It was found that the re-designed system is overall superior to the original one based on a comprehensive performance measure established in this research that considers the peak transient and residual inter-story drift angles as well as the peak base shear demand. Moreover, compared with the original system, the re-designed system was found to have similar seismic demands on the acceleration-sensitive or velocity-sensitive nonstructural components but larger seismic demands on the displacement-sensitive nonstructural components. Accordingly, the displacement-sensitive nonstructural components should be designed with caution in the low-rise MRF with the re-centering beam-to-column connections.