Accession Number:

ADA379961

Title:

Factors Influencing Low-Cycle Crack Growth in 2014-T6 Aluminum Sheet at -320 F (77 K)

Descriptive Note:

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER

Personal Author(s):

• Pierce, William S.
• Sullivan, Timothy L.

Report Date:

1969-04-01

Pagination or Media Count:

45.0

Abstract:

An investigation was conducted to determine the low-cycle under 10 000 cycles crack growth characteristics of through- center- cracked specimens 0.060 in. 0.152 cm thick subjected to tension-tension cyclic loading. The following factors were studied 1 minimum to maximum initial stress intensity ratio R sub i 2 the maximum gross stress applied, as percentage of critical fracture stress and 3 cyclic rate. The crack growth rate was found to be a function of stress level expressed as percentage of critical fracture stress for specimens tested at the same R. value. A crack growth relation was developed which takes into account changes in R. in the low-cycle region. When the cycle rate was decreased from 0. 5 to 0.05 Ha, the cyclic life was reduced, but only for high initial stress intensities.

Descriptors:

• *ALUMINUM ALLOYS
• *CRACK PROPAGATION
• *LIFE CYCLES
• STRESSES
• RATIOS
• LOADS(FORCES)
• INTENSITY
• RATES
• FRACTURE(MECHANICS)
• CYCLES
• TENSION
• CYCLIC RATE

Subject Categories:

• Properties of Metals and Alloys
• Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE