| Autor: |
Jeffrey W. Sowards, Timothy S. Weeks, Ross A. Rentz, David T. Read, Enrico Lucon |
| Rok vydání: |
2016 |
| Předmět: |
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| Zdroj: |
Volume 3: Operations, Monitoring and Maintenance; Materials and Joining. |
| Popis: |
This paper reports an extension of a previous study that compared methods of evaluating J by the crack mouth opening displacement and by surface strain gradients. Here, the surface strain gradients are measured by three-dimensional digital image correlation. The results herein represent a small test matrix that involved evaluation of the J-integral for clamped single-edge notched tensile specimens from API 5L X65 base-metal, weld metal and the adjacent heat affected zone; the J-integral was evaluated by a standardized procedure utilizing the crack mouth opening displacement (CMOD) and by the contour integral method on an external surface strain contour. Digital image correlation provides sufficient full-field strain data for use by this method and is considerably more robust than surface-mounted strain gage instrumentation. A series of validity checks are presented that demonstrate that the data are useful and valuable. Experimental determination of the J-integral is not limited to thoroughly analyzed test geometries and may be achieved with limited instrumentation. Furthermore, the method described does not require a determination of crack size nor any instrumentation that requires access to the crack mouth. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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