Predicting fatigue resistance of nano-twinned materials: Part II - Effective threshold stress intensity factor range

Piyas B. Chowdhury, Huseyin Sehitoglu, Richard G. Rateick

Research output: Contribution to journalArticle

Abstract

The determination of ΔKth,eff for fatigue crack growth has been a challenging task. A model is forwarded to assess this parameter in presence of nano-scale twins for Cu, Ni and Al. The model utilizes the concept of irreversibility of crack emitted dislocation glide. Incremental crack extension is formulated on the basis of force balance of continuum dislocations during cyclic flow. Peierls stresses for free and twin boundary restricted glide, computed in Part I, constitute an essential ingredient in devising crack growth threshold founded on relative positions of dislocations. Predicted ΔKth,eff for relatively short cracks is shown to be substantially enhanced with a refinement in twin lamellar thickness and twin spacing as indicated experimentally in recent literature. The theoretical values of ΔKth,eff in Ni, Cu and Al are in good agreement with experimental literature for longer cracks as well. Saturation effects are observed in ΔKth,eff levels with respect to gradual increase in twin nano-dimensions as well as crack length. Mechanistic origin of these observations is discussed.

Original languageEnglish (US)
Pages (from-to)292-301
Number of pages10
JournalInternational Journal of Fatigue
Volume68
DOIs
StatePublished - Nov 2014

Keywords

  • Annealing twin
  • Fatigue threshold
  • Microstructure
  • Short crack growth
  • Slip irreversibility

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Predicting fatigue resistance of nano-twinned materials: Part II - Effective threshold stress intensity factor range'. Together they form a unique fingerprint.

  • Cite this