NONLINEAR SEISMIC ANALYSIS OF INFILLED RC FRAMES WITH AN EQUIVALENT STRUT MODEL

The objective of this paper was to simulate the seismic response of RC infilled frames. In order to evaluate the behaviour of these structures, it was fundamental to define an appropriate analytical model. Several models were proposed in literature for the masonry infills. In this study the equivalent strut model was considered. The study started from the model for monotonic loading proposed by Al-Chaar. This model was extended to the case of cyclic loading by calibrating the degradation of strength and stiffness, the residual strength and the loading and unloading branches. This calibration was performed by comparing the analytical results with the ones of available experimental tests on infilled frame. The model was then applied for investigating the seismic response of infilled RC frames: pushover and nonlinear dynamic analyses were carried out for obtaining the response in terms of base shear-top displacement and to assess the configuration of collapse.