Method to analyse multiple site damage fatigue before and after crack coalescence

The Multiple Site Damage is a phenomenon that appears in e.g. aircraft fuselages and weld geometries. This article introduces a method for solving the Multiple Site Damage fatigue in a 2D specimen. The cases studied are for Linear Elastic Fracture Mechanics situations, isotropic materials and crack growth governed by the Paris Law regime. Already known fracture mechanics concepts are merged together in an innovative algorithm that increases computational efficiency by optimizing the number of Finite Element Analyses necessary for fatigue calculations. A new approach to crack coalescence is presented by using the application limit of Linear Elastic Fracture Mechanics. Comparisons with analytical, experimental and other software results have shown the reliability of this method for several cases. A final explanatory example of a plate with multiple cracks and a hole shows the capabilities of the method proposed.