Analysis of crack propagation in welded stiffened panels

Models are developed to predict the growth of long fatigue cracks in stiffened panels. An analytical model is described that estimates the stress intensity factor based on superposition of linear-elastic fracture mechanics solutions, taking into account the typical residual stress patterns in stiffened panels. The results were confirmed by finite element analyses. The computed stress intensity factors, alongwith the Paris law, are used to predict the crack propagation in box girders with welded stiffeners with reasonable accuracy.