Análise numérica e experimental da evolução de flechas de vigas de concreto armado sob ações cíclicas repetidas

This paper discusses the structural behavior of reinforced concrete beams subjected to cyclic loadings by numerical and experimental analysis. The main objective was to quantify the increase in deflections of the beams when subjected to repeated loading cycles. Experimental tests with the application of cyclic and monotonic loading were carried out with reduced size beams. The numerical analysis utilized a simplified damage model that is part of the group denominated lumped dissipation models. This model takes into account the damage increase as a function of the increase in the number of cycles, enabling an evaluation of the stiffness loss due to repeated loads. The experimental results not only confirmed the effect of repeated loads on the stiffness loss of beams, but also demonstrated the important influence of the flexural reinforcement ratio on cyclic behavior. Comparisons between the experimental results and those obtained with the numerical model provided support for the potential of the damage model employed in the prediction of the increase of deflections caused by repeated cyclic loading.