Member, American Ceramic Society.
Crack-Shape Effects for Indentation Fracture Toughness Measurements
Article first published online: 11 JUL 2005
Journal of the American Ceramic Society
Volume 75, Issue 2, pages 305–315, February 1992
How to Cite
Smith, S. M. and Scattergood, R. O. (1992), Crack-Shape Effects for Indentation Fracture Toughness Measurements. Journal of the American Ceramic Society, 75: 305–315. doi: 10.1111/j.1151-2916.1992.tb08180.x
B. R. Lawn-contributing editor
Presented at the 93rd Annual Meeting of the American Ceramic Society, Cincinnati, OH, April 29, 1991 (Paper No. 6–JXIX–91).
Supported by the Precision Engineering Center, North Carolina State University.
- Issue published online: 11 JUL 2005
- Article first published online: 11 JUL 2005
- Manuscript No. 196491. Received August 5, 1991; approved October 30, 1991.
Various methods to measure fracture toughness using in-dentation precracks were compared using soda-lime glass as a test material. In situ measurements of crack size as a function of applied stress allow both the toughness Kc and the residual-stress factor χ to be independently determined. Analysis of the data showed that stress intensity factors based on classical half-penny crack shapes overestimate toughness values and produce an apparent R-curve effect. This is due to a constraint on crack shape imposed by primary lateral cracks in soda—lime glass. Models based on elliptical cracks were developed to account for the crack-shape effects.