Numerical methodology in fatigue analysis: Basic formulation

Numerical simulation of fatigue crack: growth in pavements could provide a simple and fast method to assess the resistance of the pavement to crack initiation and propagation under applied traffic loads. Such studies are facilitated through the development of appropriate computer algorithms and the use of high speed computers. On the basis of elastic-plastic fracture mechanics, a numerical methodology is presented in this paper to simulate fatigue crack growth and to predict fatigue life. This method utilizes two parameters, J-integral and R_curve, which characterize material elastic-plastic fracture behavior to define the crack growth criterion and find critical crack growth length. Fatigue crack propagation is simulated by shifting the R_curve along the crack growth direction. Fatigue Life is calculated by integrating the fatigue crack growth rate established in this process from initial crack length to critical crack length. A simple example is presented to illustrate the proposed methodology. The numerical result is consistent with available experimental result.