SEISMIC PERFORMANCE OF DUCTILE AND NOMINALLY DUCTILE REINFORCED-CONCRETE MOMENT-RESISTING FRAMES - II - ANALYTICAL STUDY

This paper is the second of two companion papers on the evaluation of the level of protection offered by ductile and nominally ductile reinf orced concrete structures. In the first paper, experimental results ob tained from shake table tests of two half-scale reinforced concrete mo ment resisting frames were reported. The first structure was designed as a ductile frame (force reduction factor R = 4) according to current Canadian standards; and the second structure incorporated only nomina lly ductile details (R = 2). This second paper deals with the dynamic modelling of the two structures. A simple nonlinear time-history dynam ic analysis model is presented and its predictions are compared with t he shake table test results. It is shown that inelastic deformations i n beam-column joints have a major influence on the seismic response of the structures. Approximate modelling of these joint deformations, ba sed on equivalent rotational springs, can provide a good correlation b etween numerical and experimental results.