Accession Number:

AD0656481

Title:

THERMAL FATIGUE DAMAGE UNDER A TWO-STRAIN-BLOCK HISTORY.

Descriptive Note:

Final rept. 1 Jul 63-1 Jul 67,

Corporate Author:

SEATTLE UNIV WASH DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

• Majors,Harry , Jr

Report Date:

1967-06-01

Pagination or Media Count:

119.0

Abstract:

Thermal-strain fatigue, two block strain cycling, axial tension-compression tests were performed on thin-walled tubes of annealed, type 200 nickel to study the plastic strain damage process that leads to failure in the range of 10,000 to 100,000 cycles at a mean temperature of 580F under a frequency of 60-90 cycles per hour. Plastic strain ranges are in the order of twenty to forty per cent of the total strain range. All tests showed a transient period in the first 100 cycles prior to the stress-strain hysteresis loops stabilizing. A cumulative damage theory was developed which led to the relationship for a two-strain block history. Author

Descriptors:

• (*NICKEL
• FATIGUE(MECHANICS))
• THERMAL STRESSES
• STRAIN(MECHANICS)
• DAMAGE
• CRACKS
• PLASTIC PROPERTIES
• COMPRESSIVE PROPERTIES

Subject Categories:

• Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE