Accession Number:

ADA162484

Title:

Long-Term Corrosion Fatigue of Welded Marine Steels.

Descriptive Note:

Final rept.,

Corporate Author:

SOUTHWEST RESEARCH INST SAN ANTONIO TX

Report Date:

1984-01-01

Pagination or Media Count:

412.0

Abstract:

Corrosion fatigue in welded marine steels and the effects of loading, environmental, material, and fabrication variables on fatigue resistance were reviewed. Mathematical models were formulated which quantified the important environmental and loading variables on fatigue crack initiation and propagation in the high and low cycle life regimes. The initiation model utilized the local stress-strain approach with a modified Neuber rule. The propagation model was based upon fracture mechanics with the stress intensity factor computed using an influence function approach with the uncracked stress state at the toe of the weld. It was concluded that crack initiation constitutes only a small portion of the fatigue life in a welded joint in the low-cycle regime. The analytical predictions for crack growth life generally gave good correlation with experiments on welded planar and tubular joints at low load R ratios in air and seawater environments. A probabilistic analysis was also undertaken to quantify the important variables in the high-cycle corrosion fatigue process. Using the fracture mechanics model, the analysis is indicated that the single most important variable for reliability predictions is associated with the applied loadings. Keywords Welding Marine steels Marine environment Fatigue crack propagation Long-term fatigue prediction.

Subject Categories:

  • Properties of Metals and Alloys
  • Fabrication Metallurgy
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE