FATIGUE LIFE AND PENETRATION BEHAVIOR OF A SURFACE-CRACKED PLATE UNDER COMBINED TENSION AND BENDING

The present study is to investigate the fatigue crack propagation behaviour of surface cracks subjected to combined tension and bending stress. An estimation of fatigue crack growth behaviour employed the Newman-Raju formula before penetration, and a K solution, proposed by the authors, after penetration. Crack length a(L) at penetration increases with an increase in bending stress. The calculated fatigue crack shape was in good agreement with the experimental shape. It was also found that the crack growth behaviour and the crack shape after penetration can be satisfactorily evaluated using the K solution proposed by the authors.