Fracture-Mechanics-based Modelling of Crack Growth in Concrete Beams
The quasi-brittle nature of the concrete materials causes progressive propagation of crack under mechanical load in concrete beams. In this paper, a mathematical model based on fracture mechanics is presented, which is suitable to analyze the behavior of crack initiation, the stress distribution and the crack growth in concrete beams. The proposed scheme combines the Linear Elastic Fracture Mechanics (LEFM) with the cohesive nonlinear model of fracture, to investigate stress intensity factors, strain energy release rates, and fracture stability conditions when the load increases. The mathematical formulation of governing elasticity equations, crack-tip stress fields and fracture propagation criteria allow the prediction of structural degradation. Experimental fracture parameters show that with applied loading, the length of the crack and the energy released increases with fracture. The results show that the proposed model could accurately predict the crack propagation behavior and structural instability, which could be used to improve the failure assessment accuracy of concrete structural systems.