Prof. John A. Nairn, Debond Fracture Mechanics<
University of Utah, Materials Science and Engineering Department

Microbond Test and Single-Fiber, Pull-Out Test Fracture Mechanics

Two papers listed on the publications page describe some fracture mechanics methods for analyzing experimental results from microbond tests or single-fiber, pull-out tests and calculating the interfacial, mode II fracture toughness. Those two papers are:

• C.-H. Liu and J. A. Nairn, ``Analytical Fracture Mechanics of the Microbond Test Including the Effects of Friction and Thermal Stresses," Int. J. Adhes. and Adhes., 19, 59-70 (1999).
  | Reprint (PDF file) |
• J. A. Nairn, ``Analytical Fracture Mechanics Analysis of the Pull-Out Test Including the Effects of Friction and Thermal Stresses," Advanced Composite Letters, 9, 373-383(2000).
  | Reprint (PDF file) |

These papers give analytical expressions for energy release rate due to debond growth in terms of experimental results from microbond and single-fiber, pull-out tests. The equations are straightforward, but tedious to implement in analysis software. To help those interested in using the analyses in those papers to carry out such calculations, you can download the following Microsoft Excel spread sheet that will do all the calculations for you:

• Pull-Out and Microbond Analyses

To do your analyses, read the instruction included in a "Help" work sheet in the downloaded spread sheet. The final equations implemented in that spread sheet come from the second reference above on the Pull-Out test. The analysis in that paper includes the relevant equations in the first paper as a special case for microbond tests. Most of the spread sheet is self contained, but extensive reference is made to the above two papers. It is probably thus worthwhile to also download the PDF versions of those papers as companions to the spread sheet.

Please contact me be email if you try the spread sheet and give me comments. In order to get a full fracture mechanics analysis of microbond or single-fiber, pull-out test results, you need to supply all the required experimental results. All the required experimental results are obtainable from such tests, but not all work on such tests has recorded all the necessary information. If you are lacking some required input parameters, those data set may not be sufficiently complete for a good fracture mechanics analysis.

Acknowledgement: This work was supported by a grant from the Mechanics of Materials program at the National Science Foundation (CMS-9713356).

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Last updated: October 2002