Um modelo computacional para simulação do comportamento mecânico de lajes fissuradas

Abstract

The knowledge on the mechanical behaviour of a building is fundamental for users safety. Moreover, it contributes to the efficiency of structural projects which technical and economic factors could be optimized. In reinforced concrete structures, in particular, computational models have been used for years, always aimed to simulate its performance when different types of loading are applied. Considering the concrete heterogeneity, models that simulate concrete non-linear behaviour are limited, especially after cracking propagation. The excessive cracking could occur on structures due to unexpected overloaded project cases or on structural modifications poorly executed. Studies involving this topic are relevant because they could offer engineers a useful tool to design structural reinforcements. This work proposes a model that can simulate the static and dynamic behaviour of damaged reinforced concrete slabs. A computational strategy based on Mazars’ damage model, which includes parameters associated with loss of stiffness occasioned by cracking, is implemented using the Finite Element Method. Numerical and theoretical validations of the proposed model are done evidencing its excellent performance on suggested applications. This study also presents a comparison between the dynamic results obtained by the proposed model and results from an experimental test. Finally, it suggests a relationship between the damage condition of a structure and its natural frequency of vibration decreasing that could be used in future for damage detection techniques.