Accession Number:

ADA025196

Title:

Fatigue Crack Growth in Aluminum Alloys.

Descriptive Note:

Final rept. 1 Jan-31 Dec 75,

Corporate Author:

ROCKWELL INTERNATIONAL THOUSAND OAKS CALIF SCIENCE CENTER

Personal Author(s):

Report Date:

1976-02-27

Pagination or Media Count:

15.0

Abstract:

The objective of this investigation was to further the understanding of the mechanisms by which fatigue crack propagation occurs in aluminum alloys. Two basic techniques were used to investigate and simulate the events occurring within the plastic zone preceding fracture. The plastic deformation occuring within the plastic zone of the crack tip was simulated by low cycle fatigue tests. These tests were largely unsuccessful because of the significant influence the crack initiation stage has on fatigue life and a relative insensitivity to environmental effects. The response of the crack tip to tensile holds was determined by acoustically determined crack closure measurements. The limited results reported here were encouraging and the crack closure investigation offers possibilities of describing the fatigue cracks response to simple loading spectra. Author

Subject Categories:

  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE