Evaluation of Response modification factor (R) for estimating the strength of core wall multistory buildings under seismic loads

Abstract

The objective of this research work is to study the response modification factor for concrete shear walls under seismic loads. The behavior of shear walls was analyzed using nonlinear static analysis by nonlinear finite element analysis. A parametric study was performed to assess the effect of shear wall dimensions, height, location, amount of reinforcement, and the fundamental time of the structure on the value of the response modification factor.

Response modification factor component and calculation methods were studied according to various codes which use forced based design method, this factor was studied also by nonlinear static analysis, which uses displacement based design method to calculate the value of response modification factor whose depends on element nonlinear behavior, ductility and enters the plasticity limit, where this factor plays an important role in seismic force reduction and dissipate earthquake energy into inelastic deformations.

Key words: response modification factor – pushover analysis – nonlinear static analysis – shear walls –time history analysis – capacity curve – ductility reduction factor – overstrength factor- base shear – displacement – ductility