Accession Number:

AD0773596

Title:

The Use of Small, Pre-Cracked Bend Specimens for Quality Control Purposes.

Descriptive Note:

Technical rept.,

Corporate Author:

CALIFORNIA UNIV LOS ANGELES SCHOOL OF ENGINEERING AND APPLIED SCIENCE

Personal Author(s):

• Tetelman,Alan S.
• Robinson,John N.
• Roman,Isaac

Report Date:

1973-11-01

Pagination or Media Count:

48.0

Abstract:

The difficulties involved in using valid ASTM K sub Ic specimens for quality control purposes are described. It is shown from tests on steels and titanium alloys that values of K sub Ic can be obtained at lower cost from small specimens. If fracture initiation occurs before general yield, K sub Ic can be determined from the load required to cause crack extension. If fracture occurs after general yield, K sub Ic can be determined from the critical plane strain crack tip opening displacement or from the notch root contraction. The effect of a steeply rising plane strain R-curve can be corrected by using a newly developed R-extrapolation technique. Simplified versions of the methods involved are described whereby small specimens can be used to determine whether a material satisfies specifications for quality control. These simplified versions require little or no calculation for quality control-testing once master nomographs have been drawn up. Author

Descriptors:

• *FRACTURE(MECHANICS)
• *QUALITY CONTROL
• *STEEL
• *TITANIUM ALLOYS
• CRACK PROPAGATION
• STRESS STRAIN RELATIONS
• STANDARDS
• ALLOYS
• YIELD STRENGTH
• TOUGHNESS

Subject Categories:

• Metallurgy and Metallography
• Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE