FRACTURE PROCESS ZONE ASSOCIATED WITH MIXED-MODE FRACTURE OF SICW AL2O3/

An experimental-numerical analysis based on moire interferometry and s tatic finite-element analysis was used to study the trailing fracture process zone of a SiCw/Al2O3 precracked, three-point bend specimen sub jected to mixed-modes I and II loading. Through an inverse analysis, t he crack closing stress distribution, which provided the best fit betw een the measured and computed crack opening displacements, along the f racture process zone was determined. The energy dissipation rate in th e fracture process zone accounted for about 44% of the released energy rate with the remainder being dissipated through whisker breakage and matrix fracture. The computed static stress intensity factors were us ed to predict the crack kinking angle, which agreed with the measured crack kinking angle of 5 degrees, by the maximum circumferential stres s criterion. Dynamic analysis showed that the crack propagated with a reduced energy dissipation rate.