Fracture process zone associated with mixed mode fracture of SiC sub(w)/Al sub(2)O sub(3)

• Published in: Journal of non-crystalline solids Vol. 177; no. pt 1; pp. 26 - 35
• Main Authors: Yu, Chang-Te, Kobayashi, Albert S
• Format: Journal Article
• Language: English
• Published: 01.01.1994
• ISSN: 0022-3093

An experimental-numerical analysis based on moire interferometry and static finite-element analysis was used to study the trailing fracture process zone of a SiC sub(w)/Al sub(2)O sub(3) precracked, three-point bend specimen subjected to mixed-modes I and II loading. Through an inverse analysis, the crack closing stress distribution, which provided the best fit between the measured and computed crack opening displacements, along the fracture process zone was determined. The energy dissipation rate in the 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 used to predict the crack kinking angle, which agreed with the measured crack kinking angle of 5 degree , by the maximum circumferential stress criterion. Dynamic analysis showed that the crack propagated with a reduced energy dissipation rate.