ISSN: 1945-7553
Page Count: 10

Measuring the Stress Intensity Factor for Propagating Cracks with Strain Gages

Dally, JW
University of Maryland, College Park,MD

Sanford, RJ
University of Maryland, College Park,MD

(Received 28 November 1988; accepted 17 November 1989)

Abstract

A new method for measuring the K value of a straight crack propagating in an isotropic plate is presented. A row of strain gages is placed at a constant distance above the crack line, and each gage is oriented to eliminate the second (B₀) term in a three-term representation of the strains. The method of analysis then provides a solution with three-parameter accuracy. Both static and dynamic analyses were performed, and the differences between the two were found to be small for crack velocities less than 0.3cR. The method was demonstrated with an experiment on 4340 alloy steel, and results for K at a crack velocity of 656 m/s were obtained.

Keywords:
stress intensity factor, dynamic fracture, strain gage, crack propagation toughness

Paper ID: JTE12480J
DOI: 10.1520/JTE12480J
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