Crack Opening Displacement Measurements on Small Cracks in Fatigue / JM. Larsen, JR. Jira, T. Weerasooriya
- Conference Author:
- Fracture Mechanics: Eighteenth Symposium (18th : 1985 : Boulder, Colorado)
- Physical Description:
- 1 online resource (17 pages) : illustrations, figures, tables
- Additional Creators:
- Larsen, JM., Jira, JR., Weerasooriya, T., American Society for Testing and Materials, and ASTM International
- Restrictions on Access:
- Subscription required for access to full text. and License restrictions may limit access.
- A computerized interferometric displacement gage was used to monitor the crack mouth opening behavior of naturally initiated small fatigue cracks in the high-strength alloy Ti6Al-2Sn-4Zr-6Mo. Complete load versus crack opening displacement curves were obtained for naturally initiated semicircular cracks of surface length as small as 50 ¿̐ưm. For a crack of this size, the maximum crack mouth opening displacement was less than 0.5 ¿̐ưm, and the precision of the individual displacement measurements was approximately 0.01 ?m. An excellent correlation between crack mouth opening compliance and surface crack length was demonstrated, and the data were shown to agree with an analytical expression for part-through surface cracks. A matrix of experiments was performed for a range of loading conditions, and crack growth data were plotted versus the nominal ?K and ?Keff, which was defined using crack closure measurements. Experimental measurements obtained for a small crack indicated that closure often develops discontinuously as the crack initially extends. This behavior was speculated to result from the formation of individual asperities on the fracture surface. In general, the interferometric method proved to be very effective and demonstrated a unique capability to monitor the behavior of very small fatigue cracks.
- Dates of Publication and/or Sequential Designation:
- Volume 1988, Issue 945 (January 1988)
- 9780803150362 (e-ISBN), 9780803109490, and 0803109490
- Digital File Characteristics:
- text file PDF
- Bibliography Note:
- Includes bibliographical references 24.
- Other Forms:
- Also available online via the World Wide Web. Tables of contents and abstracts freely available; full-text articles available by subscription., Full text article also available for purchase., and Also available in PDF edition.
- Reproduction Note:
- Electronic reproduction. W. Conshohocken, Pa. : ASTM International, 1988. Mode of access: World Wide Web. System requirements: Web browser. Access may be restricted to users at subscribing institutions.
- Technical Details:
- Mode of access: World Wide Web.
- Source of Acquisition:
- ASTM International PDF Purchase price USD25.
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