Article Article
Effect of Fatigue Precracking on Crack Engagement during Sonic IR Testing

A series of sonic IR tests were performed on modified eccentrically-loaded single edge tension [ESE(T)] specimens in which crack lengths were nominally identical, but the precracking load history used to develop the sharp cracks used in the tests was varied from specimen to specimen. A measure for crack engagement length, defined as the length of crack that develops heat during sonic IR inspection was established for these tests. The result suggest that, in a certain regime, crack engagement length correlates with fatigue opening load, which is the stress intensity factor at which the crack front is fully open during the fatigue precracking. The implication of this is that laboratory test results for sonic IR should be performed with test specimens that have undergone careful precracking procedures, and that these procedures should be reported with test results.

1. L. D. Favro, X. Han, Z. Ouyang, G. Sun, H. Sui, and R. L. Thomas. Rev. Sci. Instrum. 71:2418–2421 (2000). 2. D. L. Favro, X. Han, Z. Ouyang, H. Sui, G. Sun, L. R. Thomas. Infrared Imaging of Ultrasonicaly Excited Subsurface Defects in Materials. U.S. Patent 6,236,049. May, 2001. 3. L. D. Favro, R. L. Thomas, X. Han, Z. Ouyang, G. Newaz, and D. Gentile. Int. J. Fat. 23:S471–S476 (2001). 4. R. B. Mignogna, R. E. Green, J. C. Duke, E. G. Henneke, and K. L. Reifsnider. Ultrasonics 19:159–163 (1981). 5. A. Mian, X. Han, S. Islam, and G. Newaz. Composites Science and Technology 64:657–666 (2004). 6. C.-H. Wong, J. C. Chen, and W. T. Riddell. Proceedings of the 35th Annual Review of Progress in Quantitative Nondestructive Evaluation, AIP Conference Proceedings 1096:481–488 (2008). 7. J. C. Chen, J. Kephart, K. Lick, and W. T. Riddell. Nondestructive Testing and Evaluation 22:83–92 (2007). FATIGUE PRECRACKING FOR SONIC IR 33 8. W. Elber. Eng. Fracture Mech. 2:37–45 (1970). 9. I. Y. Solodov. Ultrasonics 36:383–390 (1998). 10. M. Richardson. Int. J. Engng. Sci. 17:73 (1979). 11. O. Rudenko and A. V. Chin. Acoust. Phys. 40:593–596 (1994). 12. A. Mian, G. Newaz, X. Han, T. Mahmood, and C. Saha. Composites Science and Technology 64:1115–1122 (2004). 13. A. Baltazar, S. I. Rokhlin, and C. Pecorari. J. Mech. Phys. Solids 50:1397–1416 (2002). 14. D. Hull. Fractography: Observing, Measuring, and Interpreting Fracture Surface Topography, pp. 283–285. Cambridge University Press, Cambridge, UK, (1999). 15. J. Lu, X. Han, G. Newaz, L. D. Favro, and R. L. Thomas. Nondestructive Testing and Evaluation 22:127–135 (2007). 16. N. J. Adams. Eng. Fracture Mech. 4:543–554 (1972). 17. S. Purshothaman and J. K. Tien. Scripta Metall. 9:923–926 (1975). 18. N. Walker and C. J. Beevers. Fat. Fract. Eng. Mat. Struct. 1:135–148 (1979). 19. K. Endo, K. Komai, and Y. Matasuda. Bull. JSME 24:1319–1325 (1981). 20. S. Suresh, G. F. Zaminski, and R. O. Ritchie. Metall. Trans. 12A:1435–1443 (1981). 21. J. C. Newman Jr. ASTM STP 1372, ASTM, West Conshohocken, PA. pp. 227–251 (2000). 22. J. C. Newman, Jr. ASTM STP 748. ASTM: Philadelphia, pp. 53 (1981). 23. ASTM Standard E647–08. Standard Test Method for Measurement of Fatigue Crack Growth Rates. ASTM International (2010). 24. ASTM Standard E399–09. Standard Test Method for Linear-Elastic Plane Strain Fracture Toughness, KIC of Metallic Materials. ASTM International (2010). 25. J. Zuidema. Square and Slant Fatigue Crack Growth in AL 2024, Delft University Press, Delft (1995). 26. X. Han, Z. Zeng, W. Li, M. Islam, J. Lu, V. Loggins, E. Yitamben, L. D. Favro, G. Newaz, and R. L. Thomas. J. Appl. Phys. 95:3792–3797 (2004). 27. J. C. NewmanJr. Int. J. Fract. 24:R131 (1984). 28. B. Budianski and J. W. Hutchinson. J. Appl. Mech. 45:67–276 (1978). 29. R. C. McClung. Engng. Mater. Struct. 14:455–468 (1991). 30. W. T. Riddell, R. S. Piascik, M. A. Sutton, W. Zhao, S. R. McNeill, and J. D. Helm. ASTM STP 1343, pp. 157–174. West Conshohocken, PA (1999). 31. T. L. Anderson Fracture Mechanics Fundamentals and Applications. Boca Raton, Florida: CRC Press (1991). 32. J. A. Newman, W. T. Riddell, and R. S. Piascik. Fat. Fract. Eng. Mat. Struct. 26:603–614 (2003). 33. J. A. Newman, W. T. Riddell, and R. S. Piascik. Fat. Fract. Eng. Mat. Struct. 26:615–625 (2003).
Usage Shares
Total Views
28 Page Views
Total Shares
0 Tweets
0 PDF Downloads
0 Facebook Shares
Total Usage