Influence of design parameters on seismic response of post-tensioned steel MRF systems

Post-tensioned (PT) steel moment-resisting frame (MRF) systems are a new system and little is known about the influence of design parameters on their seismic response. This paper reports on a study that evaluates the influence of three different design parameters on the seismic response of PT MRFs. The three design parameters are: the connection strength, the panel zone strength, and an increase in the connection strength in the upper floors. Five prototype six-storey steel PT MRFs were designed with different combinations of these design parameters. Nonlinear dynamic time history analyses of the five PT MRFs were used evaluate the influence of these parameters on the seismic response. A practical range of connection strength was identified that provides acceptable performance. The analyses indicated that the panel zone strength does not significantly affect the seismic response, and that increasing the connection strength in the upper floors improves the seismic response of the frame. (C) 2007 Elsevier Ltd. All rights reserved.