Quantitative Fracture Properties in the Transition Region and Near Transition Region for Thin Plate Ship Steel

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Authors
  1. KarisAllen, K.J.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN);Facts Engineering Inc, Halifax NS (CAN)
Abstract
Accurate characterization of mechanical materials properties is integral to the development of marine platform designs, which will exhibit acceptable levels of damage tolerance under extreme service conditions. A study has been performed to evaluate several laboratory test procedures for the characterization of fracture toughness in the ductile to brittle transition region. Test procedures evaluated include ASTM E-604, ASTM E-813, and strain energy density generated from uniaxial tension specimens. Marine structural steels and wledments used in the evaluation include CSA G40.21 350WT, CSA G40.21 38WT, and ASTM A-517. A comparison of transition curves generated from pressed-notch ASTM E-604 specimens and fatigue precracked specimens indicates that the pressed-notch specimen geometry provides an acceptable approximation of structural transition. The addition of side grooves to E-604 specimens produced out of plane crack propagation resulting in significant scatter in the transition curve results. Elastic and elastic-plastic fracture toughness tests conducted on 350WT plate specimens revealed limit load tearing in the L-T crack plane orientation and J-controlled crack extension in the T-L orientations. GSA G40.21 350WT weldments tested generated inconsistent results ranging from initiation of a brittle instability at -30C to limit load tearing at -50C. TRUNCATED
Keywords
Dynamic tear;350WT steel;Fracture transition;Fracture toughness;Dynamic Tear Transition Curve;Elastic Plastic Fracture Toughness;ASTM E604;Tensile tests;Extensometer;Strain energy density
Report Number
DREA-CR-1999-165 — Contractor Report
Date of publication
01 Oct 1999
Number of Pages
51
DSTKIM No
CA000840
CANDIS No
512604
Format(s):
Hardcopy;Document Image stored on Optical Disk

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