Journal of Materials Science

, Volume 35, Issue 8, pp 1857–1866

Effect of strain rate on stepwise fatigue and creep slow crack growth in high density polyethylene

  • M. Parsons
  • E. V. Stepanov
  • A. Hiltner
  • E. Baer
Article

DOI: 10.1023/A:1004741713514

Cite this article as:
Parsons, M., Stepanov, E.V., Hiltner, A. et al. Journal of Materials Science (2000) 35: 1857. doi:10.1023/A:1004741713514

Abstract

The effects of frequency and R-ratio (the ratio of minimum to maximum stress in the fatigue loading cycle) on the kinetics of step-wise crack propagation in fatigue and creep of high density polyethylene (HDPE) was characterized. Stepwise crack growth was observed over the entire range of frequency and R-ratio examined. A model relating crack growth rate to stress intensity factor parameters and applied strain rate was proposed by considering the total crack growth rate to consist of contributions from creep and fatigue loading components. The creep contribution in a fatigue test was calculated from the sinusoidal loading curve and the known dependence of creep crack growth on stress intensity factor in polyethylene. At a very low frequency of 0.01 Hz, fatigue crack growth rate was found to be completely controlled by creep processes. Comparison of the frequency and R-ratio tests revealed that the fatigue loading component depended on strain rate. Therefore, crack growth rate could be modeled with a creep contribution that depended only on the stress intensity factor parameters and a fatigue contribution that depended on strain rate.

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • M. Parsons
    • 1
  • E. V. Stepanov
    • 1
  • A. Hiltner
    • 1
  • E. Baer
    • 1
  1. 1.Department of Macromolecular Science and the Center for Applied Polymer ResearchCase Western Reserve UniversityClevelandUSA