Mixed mode fracture toughness and low cycle fatigue behavior in an HSLA-80 steel

Journal Article · Tue Aug 11 04:00:00 EDT 1998 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(98)00185-7· OSTI ID:653117

Kannan, K; Hirth, J P ^[1]

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1. Washington State Univ., Pullman, WA (United States). School of Mechanical and Materials Engineering

Many structural components experience a combination of loads such as tension, torsion and shear. There has been an increasing number of studies of fracture toughness under loading conditions other than pure Mode I and under mixed mode loading conditions. In several high toughness materials (which fail by a microvoid nucleation and growth mechanism) the addition of a Mode III component to a Mode I-loaded sample leads to: (1) lower values of J{sub tc}, the overall critical value of J for stable crack growth and/or (2) lower values of dJ/da, beyond J{sub tc}. For example, with the introduction of a progressively increasing Mode III component, the values of J{sub tc} for a rotor steel dropped from 190 kJ/m{sup 2} in pure Mode I to a minimum of 98 kJ/m{sup 2} before increasing again. For a steel similar to that studied here, a significant drop in J{sub tc} did not occur with the introduction of mixed modality, but the dJ/da value was observed to exhibit a drop. The studies indicate that pure Mode I by itself is not a conservative design criterion for such tough materials. In this paper, the authors report the results of mixed mode fracture toughness testing on a modified ASTM A710 grade steel, designated HSLA-80, with applications in ship hulls. Preliminary results of low cycle fatigue crack growth behavior are also presented.

• OSTI ID: 653117
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 6 Vol. 39; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL COMPOSITION
CRACK PROPAGATION
FATIGUE
FRACTURE MECHANICS
FRACTURE PROPERTIES
LOW ALLOY STEELS