Chapter 34. Compliance and Crack-Bridging Analysis for Alumina Ceramics
- Mrityunjay Singh and
- Todd Jessen
Published Online: 26 MAR 2008
Copyright © 2001 The American Ceramic Society
25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3
How to Cite
Ebrahimi, M.E., Chevalier, J. and Fantozzi, G. (2001) Compliance and Crack-Bridging Analysis for Alumina Ceramics, in 25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3 (eds M. Singh and T. Jessen), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294680.ch34
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 2001
Print ISBN: 9780470375730
Online ISBN: 9780470294680
Crack propagation of high purity alumina ceramics was investigated with Single-Edge-Notched Bending (SENB) and Double Torsion (DT) methods. The aim of this study was to use the compliance data as a tool for determining the bridging-stress distributions and evaluation of R-curve in alumina ceramics.
R-curves were obtained on the SENB specimens by a compliance-based analysis and in-situ measurements of crack length. Although the compliance analysis leads to a higher crack length only at the beginning of the test, it results in an underestimate of the real crack length. The overestimate of crack length at the beginning of the test in the compliance method could result from the development of several small cracks and microcracks in proximity of notch tip and non-plane crack profile shortly after load application, while the underestimate obviously is related to elastic crack bridging ligaments and crack border interactions leading to the R-curve behavior.
The compliance of DT specimens with successive renotching and without renotching was compared. A systematic approach for determining crack bridging stresses of the crack wake from the results of compliance measurements was extended for different grain sizes of alumina ceramics. By this compliance analysis, the KR- curve of alumina ceramics can be predicted from the compliance function, π(δa), versus the crack extension, δa. The π(δa) increases with crack extension, then shows a plateau for crack extension higher than 5 mm for finegrained alumina. For coarse-grained alumina the compliance function increases monotonically with evolution of crack bridges over several millimeters of crack extension and then reaches to plateau (π = 1.25 mm) after more than 12 mm.