LOAD AND ENVIRONMENT INTERACTIONS IN FATIGUE CRACK GROWTH

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)

• Supplemental Notes:
  • Presented at the Conference on the Prospects of Advanced Fracture Mechanics, held at Delft (Netherlands) on 24-28 Jun 74.
• Corporate Authors:

  Lehigh University

  Institute of Fracture and Solid Mechanics
  Bethlehem, PA  United States  18015

  Office of Naval Research

  Department of the Navy, 800 North Quincy Street
  Arlington, VA  United States  22217
• Authors:
  • Shih, T T
  • Wei, R P
• Publication Date: 1974-5

Media Info

• Pagination: 26 p.

Subject/Index Terms

• TRT Terms: Corrosion; Cracking; Fatigue (Mechanics); Fatigue cracking; Fracture mechanics
• Uncontrolled Terms: Corrosive environments; Fatigue life
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00072879
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: IFSM-74-61 Tech Rpt., TR-2
• Contract Numbers: N00014-67A-0370-0008
• Files: TRIS
• Created Date: Jan 9 1975 12:00AM