Abstract

In previous investigations [Chopra and Goel, 2001], the Modal Pushover Analysis (MPA) procedure was demonstrated to be accurate enough in estimating floor displacements and story drifts, and identifying locations of most plastic hinges for Moment Resistant Frame (MRF) systems. The principal objective of this investigation is to implement MPA procedure to analyze Friction Damped Braced Frame (FDBF) Systems. The comparisons of the seismic responses of the FDBF determined by MPA with Nonlinear Response History Analysis (NL-RHA) procedure illustrate that for a FDBF system, the MPA procedure is probably accepted in estimating floor displacements, but for the story drift of the structure, the accuracy of the MPA is too poor to be accepted. This leads to the introduction of an improved modal pushover analysis (IMPA) procedure. Comparing the seismic demands determined by IMPA procedure, FEMA-273 pushover analysis [Building Seismic Safety Council, 1997], and NL-RHA, it is demonstrated that the IMPA procedure is also better than FEMA-273 pushover analysis in determining the floor displacement, story drifts and the plastic slip of the friction damped bracing. (Abstract shortened by UMI.)