Simple Nonlinear Seismic Analysis of R/C Structures

A simple analytical model is developed for the calculation of the seismic displacement history response of reinforced concrete frame and frame-wall structures. The computer cost for the model is approximately three precent of that for a MDOF system. A structure is idealized as a single-degree system consisting of a mass mounted on a rigid bar connected to the ground by a hinge and a nonlinear rotational spring. The primary force-deformation relationship for the spring is obtained by a static analysis of the multistory structure. To account for stiffness changes during an earthquake, a simple hysteresis model comprising only four rules is developed. The model is examined for eight small-scale ten-story reinforced concrete test structures, and the analytical results are compared with the measured response histories. The model is shown to be successful in most instances.