Mechanical model and seismic performance of frames with a self-centring connection

The desired structural performance of a novel self-centring pinned beam-column connection with friction dampers (SC-PC-FD) has been reported. An accurate mechanical model of the SC-PC-FD connection is required for easy modelling of frames with these connections using common commercial structural analysis and design software. This paper presents a simple mechanical model for a SC-PC-FD connection. The accuracy of the model was verified using results from experimental and numerical studies on two-strand and four-strand SC-PC-FD connections. Moreover, the seismic performance of frames with SC-PC-FD connections was evaluated using incremental dynamic analysis and compared with that of moment-resisting frames. For this purpose, one-, three- and five-storey building models with moment connections and SC-PC-FD connections were designed. The two-dimensional frames were subjected to far-field, pulse near-field and no-pulse near-field earthquake records and the collapse margin ratios (CMRs) and fragility curves of the models were obtained. The developed component-based mechanical model accurately predicted the monotonic and cyclic behaviour of the SC-PC-FD connection. With the novel SC-PC-FD system, the maximum residual interstorey drift ratio and the number of developed plastic hinges at the main members of the self-centring models were reduced significantly, while the CMRs were increased.