Bond parameters for peeling and debonding in thin plated RC beams subjected to mixed mode loading – Framework

Studies have primarily focussed on predicting mode-II debonding failure; whereas, in real-case-scenario, flexurally strengthened reinforced concrete (RC) beams observe premature failure mechanisms under mixed-mode loading conditions engaging geometrical and material variations. Peeling is a consequence of flexural crack as debonding is of interfacial shear crack. Under bending, peeling failure is considerably catastrophic over debonding due to the nature of crack formation; therefore, this needs to be distinguished in predictive analysis. In this paper, a new numerical modeling methodology is approached using eXtended finite element method (xFEM) for flexural cracks and Cohesive Zone Model (CZM) for shear cracks without predefining crack locations. The parameters of the constitutive models are identified through comparing finite element results with the experimental data. These parameters are related to key material properties. Based on proposed framework, the models provide a good estimation of plate strain distribution, cracks and failure type, in terms of mode and load of failure. Bilinear bond-slip curve is a closer match over exponential crack evolution at interface.