ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 8

Monitoring Crack Extension in Fracture Toughness Tests by Ultrasonics

Klima, SJ
Materials research engineers, National Aeronautics and Space Administration Lewis Research Center, Cleveland, Ohio

Fisher, DM
Materials research engineers, National Aeronautics and Space Administration Lewis Research Center, Cleveland, Ohio

Buzzard, RJ
Materials research engineers, National Aeronautics and Space Administration Lewis Research Center, Cleveland, Ohio

Abstract

An ultrasonic method was used to observe the onset of crack extension and to monitor continued crack growth in fracture toughness specimens during three-point bend tests. A 20-MHz transducer was used with commercially available equipment to detect average crack extension less than 0.09 mm. The material tested was a 300-grade maraging steel in the annealed condition. A crack extension resistance curve was developed to demonstrate the usefulness of the ultrasonic method for minimizing the number of tests required to generate such curves.

Keywords:
ultrasonic tests, crack propagation, fractures (materials)

Paper ID: JTE11370J
DOI: 10.1520/JTE11370J
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