Load and Environment Interactions in Fatigue Crack Growth.

Abstract

The influences of environment on delay and on fatigue crack growth under programmed loading were examined for a mill annealed Ti-6Al-4V alloy. Test environments included dehumidified argon, air (with 30-60% relative humidity), distilled water, and 3.5% NaCl solution. The effects of load sequence and block size on fatigue under programmed loads were investigated also. Experimental results show that the mildly aggressive environments (atmospheric moisture and distilled water) have little effect on delay. Salt solution, on the other hand, has a significant effect on delay and on crack growth under programmed loading; the effect on delay being dependent on frequency or hold-time. Both load sequence and block size can significantly alter fatigue life under programmed loading. The need for further fundamental understanding of load and environment interactions in fatigue is discussed. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1974
Accession Number
AD0785249

Entities

People

  • Robert P. Wei
  • T. T. Shih

Organizations

  • Lehigh University

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Biological Phenomena
  • Continuum Mechanics
  • Ecological And Environmental Phenomena
  • Environment
  • Fatigue Life
  • Fracture (Mechanics)
  • Frequency
  • Humidity
  • Mechanics
  • Moisture
  • Netherlands
  • Physics
  • Sequences

Readers

  • Applied Combinatorial Optimization and Logic Circuit Design.
  • Materials Science (Mechanical Engineering).
  • Structural Health Monitoring of Composite Structures.