Comparative Study of Performance Based Plastic Design of R.C and Composite (Cfrst) Moment Resisting Frames Based on Inelastic Response Analysis

Abstract

Performance based plastic design method has emerged as a most promising and efficient seismic design method which explicitly accounts for the inelastic behavior of structural system in the design process, using the concept of energy balance applied to a pre-selected target drift and yield mechanism as design criteria based on “strong column –weak beam concept” with proper strength and ductility. In the present study comparison of a ten-storey R.C and Composite (CFRST column and Steel beam) moment resisting frames are designed by the PBPD method in terms of lateral force distribution, and the seismic performance of MRF is evaluated by non-linear static pushover analysis and non-linear dynamic time history analysis under five different ground motions using the ETABS-2013 software, with user defined hinge properties. From the above studies it is found that for nonlinear static pushover analysis shows formation of hinges in beams and at the base of the columns only for both frames leading to increased performance which clearly indicates that the PBPD method gives economical sections in terms of the optimum capacity utilization, but it is observed that the composite MRF has better yield mechanism compared to R.C MRF. From the nonlinear time history analysis it has been seen that the ground motions causes larger displacements and acceleration in the PBPD of Composite frame as compared to R.C frame. Hence it is concluded that composite moment resisting frame has performed better for high seismicity as compared to R.C moment resisting frame.