The effect of yield strength mismatch on CTOD and J estimation procedures for weld metal fracture toughness determination

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:205432

Pisarski, H G ^[1]; Wang, Y Y; Kirk, M; Gordon, R ^[2]

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1. TWI, Cambridge (United Kingdom). Structural Integrity Dept.
2. EWI, Columbus, OH (United States)

Finite element analyses and experiments were conducted on single edge notch bend fracture toughness specimens with weld metal yield strength mismatch, and J and CTOD values estimated. Weld metal mismatch was achieved by keeping the same weld metal and changing the strength of the parent plate. It is shown that for deeply cracked specimens (a/W = 0.5), the standard (ASTM E1290, BS 7448) estimation procedures for initiation J and CTOD are reasonably accurate (to within {+-}10%) for mismatch levels of {+-}25%. Similar experimental fracture toughness transition curves were obtained for mismatch levels of + 9% and {minus}20%. However, R-curve behavior appeared to be affected by mismatch. For shallow cracked specimens (a/W = 0.1), alternative estimation procedures based on the area under the load versus crack mouth opening displacement curve and appropriate {eta} values are necessary to obtain estimates of J and CTOD. These alternative procedures provide reasonably accurate estimates of initiation J (to {+-}10%) and CTOD ({+-}15%) for mismatch levels of {+-}25 both deep and shallow cracked specimens.

• OSTI ID: 205432
• Report Number(s): CONF-950695--; ISBN 0-7918-1309-6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CRACK PROPAGATION
FRACTURE MECHANICS
FRACTURE PROPERTIES
MATERIALS TESTING
MATHEMATICAL MODELS
OFFSHORE PLATFORMS
STEELS
WELDED JOINTS
YIELD STRENGTH