PERCOLATED CRACKS IN A SOLID CONTAINING MANY INITIAL DEFECTS

Hydrogen-induced fracture of steel is characterized by the formation o f internal voids caused by hydrogen precipitation at an inclusion-matr ix interface, followed by the formation of microcrack array under the superposed action of internal hydrogen pressure and external forces. T he propagation of the hydrogen-induced fracture is considerably random and the fracture develops by stepwise linking of the microcracks. Cra ck growth in a solid containing many initial defects is studied by Mon te Carlo simulation on a square lattice. Each initial defect is assume d to have two crack tips like the Griffith crack and percolated crack patterns in homogeneous medium are investigated. The effect of the den sity of the initial defects and the lattice size on percolation charac teristics is also studied.