SIMULATION OF THE GROWTH OF NEAR-SURFACE DEFECTS

The growth of near-surface circular and elliptical defects is simulate d by using an eigenstrain-based solution for the crack front stress in tensity factor. From these results the crack growth rate at all points is inferred from Paris' law, and the crack front is advanced. The str ess intensity factors are re-evaluated, and the new crack front shape implied by Paris' law found. This process, which allows the crack fron t shape to evolve freely, is repeated until final fracture occurs. The results are then compared with predictions of component life based on simplified ''engineering'' analysis, where the crack shape at each st age during its life is idealised as an ellipse (if buried) or a semi-e llipse (if surface-breaking). (C) 1998 Elsevier Science Ltd. All right s reserved.