SEDL / STP / STP803V2-EB / STP36787S

Specimen Geometry and Extended Crack Growth Effects on J^I-R Curve Characteristics for HY-130 and ASTM A533B Steels

Davis, DA
David W. Taylor Naval Ship R&D Center, Annapolis, Md.

Vassilaros, MG
David W. Taylor Naval Ship R&D Center, Annapolis, Md.

Gudas, JP
David W. Taylor Naval Ship R&D Center, Annapolis, Md.

Pages: 29    Published: Jan 1983

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Abstract

An evaluation of the ductile fracture toughness and J^IR curve properties of HY-130 and ASTM A533B-HSST-03 steels in response to systematic variations of thickness and crack length in the side-grooved compact specimen geometry was carried out. A series of 2T compact specimens was produced to varying thicknesses, and with various fatigue crack lengths. Elastic compliance J^I-R curve tests were performed, and analyses ofJ^Ic, the slope of the J^IR curve, the accuracy of the Ernst-Paris-Landes approximation for J^I and an assessment of the ω criterion for J-controlled crack growth were carried out. Results showed that J^Ic of both steels was geometry independent when validity criteria were met. Both steels displayed a clear dependence of the slope of the J^I-R curve as related to thickness/ligament ratio and degree of crack extension. A limiting thickness/ ligament ratio of 1 is necessary to ensure a conservative J^IR curve slope over the full range of crack growth. The Ernst-Paris-Landes expression was shown to accurately describe J^I to crack extension values of 0.4 b⁰ for HY-130 steel. Limited evidence suggests that a minimum value of ω to guarantee J-controlled crack growth with compact specimens in HY-130 steel is 2.