Accession Number:

AD0808787

Title:

THE CYCLIC STATE OF MATERIALS AND THE RELATIONSHIP TO MECHANICAL PROPERTIES AND FATIGUE

Descriptive Note:

Final rept. Apr 1965-Aug 1966

Corporate Author:

PHILCO NEWPORT BEACH CA AERONUTRONIC DIV

Personal Author(s):

Report Date:

1966-11-01

Pagination or Media Count:

144.0

Abstract:

This report contains the results of an experimental and theoretical study relating to the stabilized cyclic state of materials. The objectives accomplished in the program were 1 the experimental verification of the important role played by the cyclic state in fatigue 2 the correlation of virgin material properties with the cyclic stress-strain curve for four materials 2024-0 and 2024-T351 aluminum alloy plus annealed and hard OFHC copper and 3 the application of the cyclic stress-strain curve to fatigue analysis. Both constant load-range and constant strain-range fatigue tests up to fatigue-lifes of 10000 cycles were performed under axial loading conditions at speeds of 3 to 15 cyclesminute. Specimens were of circular cross-section with a one-inch gage length and longitudinal strain measurements were made with a dual- range mechanical extensometer. Power-law relationships were developed from the elastic and plastic components of stabilized strains, and these were related to true fracture stress and failure strain. Both cyclic stress-strain envelope curves and cyclic stress-strain curves were developed and employed in fatigue analyses to predict the effect of mean stresses on the fatigue life. A brief series of dual-level cumulative fatigue tests were performed in the low-life fatigue region.

Subject Categories:

  • Metallurgy and Metallography
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE