The Effects of a Single Mode III Loading Cycle on Mode I Crack Initiation and Growth Toughnesses in a Cross-Ply [90°/0°]2s Ti-6A1-4V/SiCf Composite

Abstract

The effects of a single Mode III loading cycle on the subsequent Mode I crack initiation and growth toughnesses in a cross-ply [90°/0°]_2s, Ti-6A1-4V/SiC_f composite have been investigated. A Mode III cycle with ΔJ _III = 8 kJ/m² was found to have no measurable effect on either the initiation or growth toughnesses. In contrast, a Mode III cycle with ΔJ _III = 14 kJ/m² resulted in a significant decrease in the subsequent Mode I crack initiation toughness. It also caused a reduction in the crack growth toughness until the crack had extended beyond the damage zone produced during the Mode III excursion. The results are rationalized on the basis of the fracture mechanisms as well as the deformation field produced by Mode III loading. The Mode III damage effect has implications for failure criteria for composites under multiaxial loading.

Keywords

cross-ply [90°/0°]2s Ti-6Al-4V/SiCf composite Mode III loading cycle Mode I crack initiation growth toughnesses

Get full access to this article

View all access options for this article.

References

1. Jeng, S. M. , J.-M. Yang and C. J. Yang . 1991. Mater Sci. Eng., A138:181-190.

2. Jeng, S. M. , P. Alassoeur and J.-M. Yang . 1992. Mater. Sci. Eng., A154:11-19.

3. Yang, J.-M. and S. M. Jeng . 1992. JOM, 44(6):52-57.

4. Backuckas, J. G., Jr., J. Awerbuch, T. M. Tan and A. C. W. Lau. 1993. ASTM STP 1189, pp. 713-720.

5. Connell, S. J. , F. W. Zok , Z. Z. Du and Z. Suo . 1994. Acta Metall. Mater., 42:3451-3461.

6. Chiu, H. P. , S. M. Jeng and J.-M. Yang . 1994. J. Mater. Res., 9:1767-1774.

7. Backuckas, J. G., Jr. , W. S. Johnson and C. A. Bigelow . 1993. J. Eng. Mater Tech., 115:404-409.

8. Johnson, W. S., S. J. Lubowinski and A. L. Highsmith. 1990. ASTM STP 1080, pp. 193-218.

9. Backuckas, J. G., Jr. and W. S. Johnson. 1994. NASA Tech. Memorandum 109082, NASA Langley Research Center.

10.

10. Raghavachary, S. , A. R. Rosenfield and J. P. Hirth . 1990. Metall. Trans., 21A:2539-2545.

11.

11. Gordon, J. A. , J. P. Hirth , A. M. Kumar and N. E. Moody . 1992. Metal. Trans., 23A:1013-1020.

12.

12. Feng, X. , A. M. Kumar and J. P. Hirth . 1993. Acta Metall. Mater., 41:2755-2764.

13.

13. Kamat, S. V. and J. P. Hirth . 1996. Acta Metall. Mater., 44:1047-1054.

14.

14. Kumar, A. M. Unpublished research.

15.

15. Connell, S. J. and F. W. Zok. Unpublished research.

16.

16. Jansson, S. , H. E. Deve and A. G. Evans . 1991. Metall. Trans., 22A:2975-2984.

17.

17. Kamat, S. V. , J. P. Hirth and F. W. Zok . 1996. Acta Metall. Mater., 44:1831-1838.

18.

18. ASTM E-813. 1994. Annual Book of Standards, Philadelphia, v. 3.01, pp. 628-642.

19.

19. ASTM E-1152. 1994. Annual Book of Standards, Philadelphia, v. 3.01, pp. 744-754.

20.

20. Broek, D. 1986. Elementary Engineering Fracture Mechanics. Dordrecht: Martinus Nijhoff Publishers, p. 249.

21.

21. Kumar, A. M. Unpublished research.

22.

22. Pan, J. and C. F. Shih . 1990. J. Mech. Phys. Solids, 38:161-181.

23.

23. Lee, T. D. , T. Goldberg and J. P. Hirth . 1979. Metall Trans., 14A:199-208.