Small time scale fatigue crack growth analysis

Zizi Lu, Yongming Liu

Research output: Contribution to journalArticle

72 Scopus citations

Abstract

A new fatigue crack growth formulation at the small time scale is proposed in this paper. This method is fundamentally different from the classical reversal-based fatigue analysis and is based on the incremental crack growth at any time instant within a cycle. It can be used for fatigue analysis at various time and length scales and is very convenient for the fatigue analysis under random variable-amplitude loadings without cycle-counting. Stress ratio effect is intrinsically considered in the proposed fatigue model since the stress state is directly used instead of using the cyclic stress range. In the proposed methodology, the reverse plastic zone concept is adopted to determine the lower integration limit during the time integral for crack length calculation. Model validation is performed using extensive experimental observations for various metallic materials under both constant amplitude and variable-amplitude loadings. Statistical error analysis is used to compare the proposed model with existing fatigue crack growth codes. Generally, very good correlations are observed between model predictions and experimental observations.

Original languageEnglish (US)
Pages (from-to)1306-1321
Number of pages16
JournalInternational Journal of Fatigue
Volume32
Issue number8
DOIs
StatePublished - Aug 1 2010

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Keywords

  • Crack closure
  • Fatigue crack growth
  • Multi-scale
  • Reverse plastic zone

ASJC Scopus subject areas

  • Modeling and Simulation
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering

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