A Cohesive fracture approach for the nonlinear analysis of load-induced degradation of vibration characteristics in RC beams

Abstract

In this work, the effects of damage on the mechanical and vibrational response of reinforced concrete structures is investigated. The proposed model is based on a cohesive interface approach able to simulate the diffuse cracking behavior typical of reinforced concrete structures, in conjunction with an embedded truss model, able to simulate interaction phenomena between steel reinforcement and surrounding concrete. The mathematical model is developed to describe in a realistic way the crack pattern and its evolution and to determine the main factors that can influence the static and dynamic response of damaged reinforced concrete structures. Their static and dynamic properties were evaluated for increasing levels of damage after the removal of the load, starting from the load level at the first crack nucleation to the load level of incipient collapse. In order to verify the accuracy and reliability of the proposed computational model, the numerical results, obtained in terms of variations of the vibrational characteristics of the system will also be compared with experimental data reported in literature. Results show the applicability and reliability of damage identification procedures based on both mathematical models and experimental data for structural systems such as reinforced concrete beams common in girder bridges.