SUMMARY OF SOME STUDIES OF BRITTLE-FRACTURE PROPAGATION
The most significant observations arising from experimental studies of brittle-fracture propagation in wide steel plates conducted as a part of SSC Projects SR-137 (Fracture Mechanics) and SR-155 (Low-Velocity Fracture) are summarized. Six-foot-wide plain plate specimens tested at an average applied stress of about 20 ksi, a temperature of 0 deg F, and with the notch-wedge-impact method of initiation, in order to study fracture propagation under relatively steady state conditions produced fracture speeds in the range of 2000 to 4000 fps. Six-foot-wide prestressed steel plates with a region of high tensile residual strain at each edge, and a region of residual compression in the central portion, tested at zero or 3 ksi average applied stress, at 0 deg F, and with impact initiation, produced fracture speeds of 6000 fps in the tensile zone near the initiation source, and speeds as low as 50 fps in the central portions of the plate. Two-foot-wide centrally notched and welded specimens fabricated in different ways and tested at an average applied stress of about 10 ksi and a temperature of -40 F, produced speeds within 1-1/2 inches of the initiation source and in a region of high residual tensile stress as high as 5000 fps whereas speeds throughout the remainder of the specimen, which initially possessed a low compressive residual stress, were on the order of 1800 fps. Fracture texture, the effects of thermal strain cycling, notch geometry, and surface strain field associated with the advancing fracture at both high and low velocities have been observed and reported.
University of Illinois, Urbana-ChampaignUrbana, IL USA 61801
Ship Structure CommitteeNational Academy of Science, 2101 Constitution Avenue, NW
Washington, DC USA 20418
- Hall, W J
- Barton, F W
- Publication Date: 1963-9-4
- Pagination: 13 p.
- TRT Terms: Cracking; Deformation curve; Fracture mechanics; Plate bearing test
- Identifier Terms: Ship Structure Committee
- Uncontrolled Terms: Crack propagation
- Subject Areas: Marine Transportation; Materials;
- Accession Number: 00331931
- Record Type: Publication
- Source Agency: Ship Structure Committee
- Report/Paper Numbers: SSC-149 Final Rpt.
- Contract Numbers: NObs-65790
- Files: TRIS
- Created Date: May 21 1981 12:00AM