High-Cycle Fatigue and Time-Dependent Failure in Metallic Alloys for Propulsion Systems.

Abstract

This program is focused on the definition, microstructural characterization and mechanism-based modeling of the limiting states of damage associated with the onset of high-cycle fatigue failure in titanium and nickel-base alloys for propulsion systems. Both experimental and theoretical studies are aimed at three areas, namely HCF/LCF interactions, the role of notches and foreign object damage, and fretting fatigue. The approach is to combine new experimental techniques for characterizing microstructural damage, with detailed micro-mechanical modeling to facilitate the prediction of the effects of such damage. During the third program year, notable highlights include the characterization and quantitative modeling of fretting and FOD, and the definition of practical "lower-bound" HCF threshold stress intensities including the role of mixed-mode loading in Ti-6Al-4V. The ultimate aim of this work is to provide a mechanistic basis for the evolution of HCF damage, enabling comprehensive life-prediction schemes to be formulated for fatigue-critical components in turbine engines.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1999
Accession Number
ADA368794

Entities

People

  • Anthony W. Thompson
  • John W. Hutchinson
  • Robert O. Ritchie
  • Subra Suresh
  • Walter W. Milligan

Organizations

  • University of California, Berkeley

Tags

Communities of Interest

  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Elastic Properties
  • Engineering
  • Engineers
  • Foreign Object Damage
  • Fracture (Mechanics)
  • Heat Treatment
  • Materials
  • Materials Engineering
  • Materials Science
  • Mechanical Engineering
  • Mechanical Working
  • Mechanics
  • Modulus Of Elasticity
  • Propulsion Systems
  • Three Dimensional
  • Turbines

Readers

  • Structural Health Monitoring of Composite Structures.
  • Systems Analysis and Design