PREDICTION OF DUCTILE BEHAVIOUR IN WELDED STRUCTURES (TRANSITION BEHAVIOUR, SHEAR LIP, NOTCH ACUITY AND SPECIMEN SIZE)

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Authors
  1. Matthews, J.R.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Abstract
Design of ships against fracture requires, at the simplest level, that the minimum service temperature of the ship coincide with the upper shelf of the structural ductile to brittle transition curve for the steel and weldments. Material specifications in shipping standards often have no requirement for notch toughness and when they do specify toughness the specimen is of insufficient size and notch acuity to reflect the structural transition behaviour and to guarantee that the structure will be ductile at the lowest service temperatures. Consequently minimum standards should be adopted and specimen size and notch acuity requirements should be sufficient to predict ductile behaviour. In this paper, it will be shown that the transition behaviour for Charpy size specimens can be 50 to 100C below that for larger Dynamic Tear specimens. It will be shown that replacing the standard notch with an EDM notch in Charpy specimens moves the transition curve towards the Dynamic Test curve but as little as 20 degrees for some materials. This leaves the Dynamic Test specimen as the simplest existing specimen whose transition behaviour would approximate that of a structure. Data will be presented for 350WT and A517 steels. Refinement of the Dynamic Tear specimen to include an EDM notch as opposed to a machined and pressed notch may marginally reduce cost of testing. TRUNCATED
Keywords
350WT steel;A517 steel;Dynamic Tear;Shear Lip
Date of publication
01 Sep 1996
Number of Pages
12
DSTKIM No
97-02664
CANDIS No
502899
Format(s):
Hardcopy;Document Image stored on Optical Disk

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