STRETCH ZONE WIDTH MEASUREMENT OF SIDE-GROOVED HSLA 80 FRACTURE SPECIMENS

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Authors
  1. MacKay, K.
  2. Chernuka, M.W.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN);MARTEC Ltd, Halifax NS (CAN)
Abstract
Stereoscopic imaging with a scanning electron microscope was used to measure stretch zone width on the fracture surfaces of side grooved HSLA 80 SENB fracture specimens which were tested over a range of temperatures (-42C to 22C) and loading rates (0.01 to 2710 mm/s). The data were examined to determine the relationship between stretch zone width and temperature at constant loading rate, and the relationship between stretch zone width and loading rate at constant temperature. Measurement error, the limited number of data points, and intrinsic variability collectively limit the confidence with which trends could be determined. For loading rates below 2 mm/s, the stretch zone width increased with temperature until a limiting temperature of -20C was reached. Beyond this temperature the variation in stretch zone was less than the measurement error. At a loading rate of 2710 mm/s, the stretch zone width appeared to increase linearly with temperature over the range of -5C to 15C. The variation in stretch zone width with loading rate was less than the measurement error over the range of 0.01 to 60 mm/s. There appeared to be a decrease in stretch zone width when the loading rate was increased to 2710 mm/s. For specimens which exhibited stable crack growth after blunting, the stretch zone width was greater in the central region of the specimen than at the edges. TRUNCATED
Keywords
Stretch zones;Fracture toughness
Report Number
DREA-CR-95-406 — Contractor Report
Date of publication
01 Oct 1994
Number of Pages
98
DSTKIM No
96-00748
CANDIS No
152127
Format(s):
Document Image stored on Optical Disk;Hardcopy

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