Accession Number:

AD0607224

Title:

ON STRAIN INCOMPATIBILITY AND GRAIN BOUNDARY DAMAGE IN FATIGUE.

Descriptive Note:

Technical rept.

Corporate Author:

COLUMBIA UNIV NEW YORK INST FOR THE STUDY OF FATIGUE AND RELIABILITY

Personal Author(s):

• Ronay,Maria

Report Date:

1964-08-01

Pagination or Media Count:

9.0

Abstract:

It is shown by observation of the cyclically deformed structure of Fcc metals that even under conditions of slip concentrated in bands, the restraint by neighboring grains significantly affects the damage developing in these bands. At higher strain amplitudes at which slip is not concentrated the restraint by neighboring grains produces grain boundary damage. The concept of strain incompatibility used to interpret the observations also implies that typical surface phenomena observed in fatigue such as notches and stiles in the surface at low strain amplitudes and rumpled surfaces due to grain distortion at high strain amplitudes are mechanisms for the relief of strain incompatibilities rather than primary causes of fatigue damage, while the significance of subgrain formation with respect to fatigue changes in the course of cyclic straining. Author

Descriptors:

• *FATIGUE(MECHANICS)
• GRAIN BOUNDARIES
• FATIGUE(MECHANICS)
• MICROSTRUCTURE
• BRASS
• COPPER
• DEFORMATION
• STRAIN(MECHANICS)
• GRAIN STRUCTURES(METALLURGY)
• FRACTURE(MECHANICS)
• SURFACE PROPERTIES
• METALS

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE