GROWTH AND LINKAGE OF CRACKS AND FORMATION OF CREEP FRACTURE PATTERN SIMULATED BY A MULTICRACK GROWTH MODEL
A computer simulation using a multicrack growth model was carried out on the growth and linkage of cracks and the formation of creep fracture pattern resulting from the initial defects. The percolated crack patterns and the number of steps to percolation were examined by Monte Carlo simulation on a square lattice. Effects of stress and grain size on creep fracture process are then discussed. The stress and grain size dependence of the number of steps to percolation in the simulation was similar to that of grain-boundary sliding in the austenitic 21Cr-4Ni-9Mn heat-resisting steel, which controlled the growth of grain-boundary cracks. The fractal dimension of the percolation crack was also correlated with that of the creep fracture pattern in the 21Cr-4Ni-9Mn steel.