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Journal of Materials Science

, Volume 42, Issue 16, pp 7004–7015 | Cite as

A fatigue-to-creep correlation in air for application to environmental stress cracking of polyethylene

  • Ravi Ayyer
  • Anne HiltnerEmail author
  • Eric Baer
Article

Abstract

The present study was undertaken to determine whether the correlation between fatigue and creep established for polyethylene in air could be extended to environmental liquids. Fatigue and creep tests under various conditions of stress, R-ratio (defined as the ratio of minimum to maximum load in the fatigue loading cycle), and frequency were performed in air and in Igepal solutions. The load–displacement curves indicated that stepwise fatigue crack growth in air was preserved in Igepal solutions at 50 °C, the temperature specified for the ASTM standard. In air, systematically decreasing the dynamic component of fatigue loading by increasing the R-ratio to R = 1 (creep) steadily increased the lifetime. In contrast, the lifetime in Igepal was affected to a much smaller extent. The fatigue to creep correlation in air was previously established primarily for tests at 21 °C. Before testing the correlation in Igepal, it was necessary to establish the correlation in air at 50 °C. Microscopic methods were used to verify stepwise crack growth by the sequential formation and breakdown of a craze zone, and to confirm the fatigue to creep correlation. The crack growth rate under various loading conditions was related to the maximum stress and R-ratio by a power law relationship. Alternatively, a strain rate approach, which considered a creep contribution and a fatigue acceleration factor that depended only on strain rate, reliably correlated fatigue and creep in air at 50 °C under most loading conditions of stress, R-ratio and frequency. The exceptions were fatigue loading under conditions of R = 0.1 and frequency less than 1 Hz. It was speculated that compression and bending of highly extended craze fibrils were responsible for unexpectedly high crack speeds.

Keywords

Fatigue Crack Growth Rate Creep Crack Growth Craze Fibril Craze Zone 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Parsons M, Stepanov EV, Hiltner A, Baer E (1999) J Mater Sci 34:3315, DOI: 10.1023/A:1004616728535CrossRefGoogle Scholar
  2. 2.
    Parsons M, Stepanov EV, Hiltner A, Baer E (2000) J Mater Sci 35:1857, DOI: 10.1023/A:1004741713514CrossRefGoogle Scholar
  3. 3.
    Parsons M, Stepanov EV, Hiltner A, Baer E (2000) J Mater Sci 35:2659, DOI: 10.1023/A: 1007354600584Google Scholar
  4. 4.
    Hu Y, Summers J, Hiltner A, Baer E (2003) J Mater Sci 38:633, DOI: 10.1023/A: 1021899801981 Google Scholar
  5. 5.
    Bernal-Lara TE, Hu Y, Summers J, Hiltner A, Baer E (2004) J Mater Sci 39:2979, DOI: 10.1023/B: JMSC.0000025823.39995.40Google Scholar
  6. 6.
    Ward AL, Lu X, Huang Y, Brown N (1991) Polymer 32:2172CrossRefGoogle Scholar
  7. 7.
    Qian R, Lu X, Brown N (1993) Polymer 34:4727CrossRefGoogle Scholar
  8. 8.
    Tonyali K, Brown HR (1987) J Mater Sci 22:3287, DOI: 10.1007/BF01161193Google Scholar
  9. 9.
    Shanahan MER, Schultz J (1979) J Polym Sci: Polym Phys Ed 17:705Google Scholar
  10. 10.
    Hittmair P, Ullman R (1962) J Appl Polym Sci 19:1CrossRefGoogle Scholar
  11. 11.
    Ward AL, Lu X, Brown N (1990) Polym Eng Sci 30:1175CrossRefGoogle Scholar
  12. 12.
    Tonyali K, Rogers CE, Brown HR (1987) Polymer 28:1472CrossRefGoogle Scholar
  13. 13.
    Mai YW, Williams JG (1979) J Mater Sci 14:1933, DOI: 10.1007/BF00551034CrossRefGoogle Scholar
  14. 14.
    Altstaedt V, Keiter S, Renner M, Scharb A (2004) Macromol Symp 214:31CrossRefGoogle Scholar
  15. 15.
    Parsons M, Stepanov EV, Hiltner A, Baer E (2001) J Mater Sci 36:5747, DOI: 10.1007/BF00705290Google Scholar
  16. 16.
    Chou CJ, Vijayan K, Kirby D, Hiltner A, Baer E (1988) J Mater Sci 23:2533, DOI: 10.1007/BF01111912CrossRefGoogle Scholar
  17. 17.
    Shah A, Stepanov EV, Hiltner A, Baer E, Klein M (1997) Int J Frac 48:159CrossRefGoogle Scholar
  18. 18.
    Shah A, Stepanov EV, Klein M, Hiltner A, Baer E (1998) J Mater Sci 33:3313, DOI: 10.1023/A: 1004360011750Google Scholar
  19. 19.
    Shah A, Stepanov EV, Capaccio G, Hiltner A, Baer E (1998) J Polym Sci: Part B: Polym Phys 36:2355CrossRefGoogle Scholar
  20. 20.
    Brown N, Ward IM (1983) J Mater Sci 18:1405, DOI: 10.1007/BFO1111960Google Scholar
  21. 21.
    Lu X, Wang X, Brown N (1988) J Mater Sci 23:643, DOI: 10.1007/BF00576763CrossRefGoogle Scholar
  22. 22.
    Berger LL, Kramer EJ (1987) Macromolecules 20:1980CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  1. 1.Department of Macromolecular Science, and Center for Applied Polymer ResearchCase Western Reserve UniversityClevelandUSA

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