To determine the crack growth path and the number of cycles for a crack to grow through the complex geometry of a fin seal. A particular challenge in this application is simulating the crack growth through the component where there is a significant change in the cross section which can result in multiple crack fronts.
A 3D BEASY model was developed to predict the crack growth. The crack growth for the most part was simulated automatically but for the situations where this was not possible the powerful features to add arbitrary crack shapes into a structure were utilised. The simulation used the minimum strain energy density criteria to predict the crack growth direction which allowed the crack to grow in the direction dictated by the stress field resulting from the loading and geometry. The rate of growth of the crack was predicted along the crack front to allow for differential crack growth and allowed the crack to respond to the redistribution of the stresses as the loading path through the component changed.
Detailed information on the crack path and number of cycles required to grow to the critical size were identified from the study.