Influence Of Beam-column Stiffness Ratio(P)on Dynamic Performance Of 2-D Frames

Vertical storey stiffness irregularity is inevitable in structures and it brings out uncertain behavior of frame structures mostly during earthquake.The behavior of a frame structure when its various floor levels have irregular stiffness is really unpredictable.The seismic response of such type of structures when analyzed by building codes or computer applications is totally different both during design period and in-service period.This issue is a concern to many researchers and practitioners.P.Sakar et.al.,Ruiz and Diederich,Moelhe,D.Rana and others attempted to investigate the extent of impact of stiffness irregularity on structural performance and the possible recommendations to minimize its in-service performance uncertainties during design.They tackled this problem from distinct angles in terms of the techniques of modeling,mode of analysis,target site,and structure's performance indicators,etc.Considering their technique for irregularity modeling,mass and strength properties were mostly used but not many times with the stiffness property.Anyway,their opinions and conclusions were similar and conformed to the various state-of-arts.This thesis investigates the influence of the stiffness irregularity on the seismic response of R/C frame using stiffness property in the form of beam/column stiffness ratio().For this purpose,linear and non-linear analyses like equivalent static,response spectrum,time-history and pushover analysis were conducted on the models.The modeling of 36 models was made faster and efficient through the application of VBA and SAP2000 OAPI programming interface.The results of analyses are presented in the thesis and they conform to most of the results by researchers like Vamudson and Nau.