Performance evaluation of masonry-infilled RC frames under cyclic loading based on damage mechanics

Based on the equivalent strut approach (simplified model), a damage model is proposed in this paper for the characterization of masonry walls submitted to lateral cyclic loads. The model, developed along the lines of the Continuum Damage Mechanics, has the advantage of including explicitly the coupling between damage and mechanical behaviour and so is consistent with the definition of damage as a phenomenon with mechanical consequences. The model includes the simulation of phenomena such as stiffness and strength degradation and pinching behaviour. The macromodel has been incorporated in a nonlinear structural analysis program for analysis of masonry-infilled RC frames. The model has been validated with some experimental tests. An evaluation of the structural performance of the analysed masonry-infilled frames has been performed based on the calculated damage values and the storey drifts.