Damage Assessment of Crack Growth Through Numerical Modelling and Rain Flow Counting Method

The performance and behavior of nearly all in-service structures can be affected by the damage resulting from external conditions such as weather, abrasion, loading condition, wear, operator misuse, or safety negligence that lead to catastrophic failure of the structures. Therefore, fatigue failures that resulted from crack growth and have a potential to cause collapse of the structures have to be managed earlier through quantifying the crack growth, for instance using the stress intensity factor (SIF). The SIF approach can calculate the stress level at the crack tip by modeling crack phenomenon under simple loading at small discrete steps using an appropriate Finite Element method with compatible software tools. In the study reported in this article, the displacement extrapolation method has been employed to calculate the SIF and rain-flow counting method is used for the analysis of fatigue data to calculate the life cycle of modeled crack growth under varying stress. The calculated stress intensity factor is useful to predict the crack propagation of the structure by the global and local detection approaches using the cycle-by-cycle integration methods. ABAQUS software and MATLAB were applied to conduct a virtual experiment on mode-I crack modeling, and the obtained results showed that this methodology could predict the crack propagation path and fatigue life of the modeled 2D structural component.