Accession Number:

AD0258024

Title:

REDUCTION OF THE ENDURANCE LIMIT AS A RESULT OF STRESS INTERACTION IN FATIGUE

Descriptive Note:

1 Feb-31 Jul 1960

Corporate Author:

COLUMBIA UNIV NEW YORK

Personal Author(s):

• Heller, Robert A.

Report Date:

1961-02-01

Pagination or Media Count:

33.0

Abstract:

This paper presents the results of an investigation of the effects of stress interaction on fatigue life of aircraft structural materials subjected to randomized load spectra. All three materials 2024 and 705 aluminum and SAE 4340 steel exhibit fatigue lives shorter than those predicted on the basis of the linear Miner damage rule. A quasi-linear rule is proposed with a variable, spectrum dependent. endurance limit producing safe life estimates the dependence of the endurance limit on the stress spectrum and its resulting design inadequacy is shown. Tests were performed on high speed, programmed, rotating bending fatigue machines of special design.

Descriptors:

• *ALUMINUM ALLOYS
• *AIRFRAMES
• *FATIGUE(MECHANICS)
• STRESSES
• LOAD DISTRIBUTION
• STRUCTURES
• STEEL
• EQUATIONS
• PLASTIC PROPERTIES
• MATHEMATICAL ANALYSIS
• TEST EQUIPMENT
• THEORY
• MECHANICAL PROPERTIES

Subject Categories:

• Properties of Metals and Alloys
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE