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U.S. Department of Energy
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Materials and mechanics of rate effects in brittle fracture. Progress report, October 1978-October 1979

Technical Report ·
DOI:https://doi.org/10.2172/5764356· OSTI ID:5764356
A thermodynamic formulation for a crack driving force has been experimentally used in linear elastic fracture mechanics, elastic plastic fracture mechanics and creep fracture. In linear elastic and elastic plastic fracture mechanics, mechanical stability criteria are established from the load versus the load point displacement in two test specimens that differ only in crack area. These tests have also been used to measure the fracture toughness in several heat treated steels. Creep cracking of PMMA has shown that there is a sharp transition to unstable fracture in a plot of the log of the steady state crack velocity versus the crack driving force at several selected temperatures. In addition, it has been shown that the athermal crack driving force is independent of rate and temperature. A new method for electronically recording the crack driving force versus the crack area has been used on double cantilevered beam specimens. Temperature and crack rate dependences have been measured near the ductile to brittle transition temperature in a low carbon steel.
Research Organization:
Rochester Univ., NY (USA)
OSTI ID:
5764356
Report Number(s):
COO-2422-22
Country of Publication:
United States
Language:
English