CYCLIC NONLINEAR BEHAVIOUR OF RC FRAMED STRUCTURES ACCOUNTIG FOR FLEXURE-SHEAR INTERACTION

摘要

Fibre beam-column elements thus far proved to be very accurate in the simulation of flexure dominated behaviour of reinforced concrete (RC) frames. However, when the shear span of the frame elements is small, the shear behaviour plays an important role in the overall response of the structure, as observed in numerous post-earthquake site observations. It is responsible for some of the most sudden and impressive failures of RC structures throughout earthquake-damaged areas. Whilst there are various modelling strategies in literature able to predict the shear response and the shear-flexure coupling under monotonic loading conditions, very few are the reported models that have demonstrated successful results under cyclic loading, as in the seismic load case.Accordingly, the present work aims at formulating and implementing, in a finite element code, a fibre beam-column model for predicting nonlinear behaviour in shear of RC framed structures. Numerical results obtained with this model are compared to experimental results. In particular, the cyclic behaviour of squat RC columns and shear walls are taken into account. It is found that the developed model is able to catch the main characteristics of the structural element shear response.