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 beha viour of surface cracks subjected to combined tension and bending stre ss. An estimation of fatigue crack growth behaviour employed the Newma n-Raju formula before penetration, and a K solution, proposed by the a uthors, 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 a uthors.