Evaluation of deflection in reinforced concrete structures using damage mechanics

Resumo

This work intends to present a contribution about a proposed approach for the estimative of displacements in reinforced concrete structures submitted to service loads. This work is restrictive to C20 up to C35 classes of strength. The approach used in this work consists in the decreasing of cracking element elastic moduli by damage model. That constitutive model takes into account induced anisotropy, plastic deformations and bimodular elastic response and a simplified version is used in order to simulate the concrete behavior, while an elastoplastic behavior is admitted for the reinforcement. Initially, a set of beams are analyzed and some parameters related to the problem are modified, such as: compression strength, span length, cross section, reinforcement rates and support conditions. The numerical responses are compared with the ones obtained by NBR 6118:2007 Procedure. Statistical analyses are carried on in order to identify the major variables in the problem. Finally, some possible proposals to obtain cracking moment and displacement values in RC structures are discussed based on numerical and statistical analyses performed in this work in order to contribute in the improvement to Brazilian Technical Code procedure.