The Use of Small, Pre-Cracked Bend Specimens for Quality Control Purposes.
CALIFORNIA UNIV LOS ANGELES SCHOOL OF ENGINEERING AND APPLIED SCIENCE
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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
- Metallurgy and Metallography
- Test Facilities, Equipment and Methods