Volume 26, Issue 2 (March 1998)
An International Survey of Small-Crack Research
A survey was conducted to determine the comment state of international research on small cracks. The survey consisted inquiries regarding the nature of the research, the materials studied,, the applications of the investigators' research, the smallest crack size monitored, the techniques used to monitor crack growth, the testing environment, the surface conditioning/preparation, and the models to predict crack growth. Survey participants were also asked to identify problem areas they were addressing with their research and other important unresolved questions regarding small cracks.
The results of the survey show that a wide range of materials, including metallics composites, rock, and bone, are currently under investigation for both basic research purposes and for particular applications. Researchers are able to monitor cracks smaller than I µm in length using one of or combinations of several different techniques.
Many crack growth models are being used to predict crack growth in these materials. The absence of a single unified crack growth model stems from the fact that the small-crack regime encompasses several different classifications, including microstructurally small cracks and mechanically small cracks. Each type of crack grows differently, thus requiring a different treatment.