Low cycle notched fatigue behavior and life predictions of A723 high strength steels

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:191356

Troiano, E; Underwood, J H; Crayon, D ^[1]

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1. Army Armament Research, Development and Engineering Center, Watervliet, NY (United States). Benet Labs.

Two types of ASTM A723 steels have been investigated for their low cycle fatigue behavior. Specimens were tested in four-point bending, both with and without notches, and the measured fatigue lives were compared with those predicted by Neubers notch analysis, and standard fracture mechanics life prediction techniques. Comparison of measured and predicted lives indicate that the elastic/plastic Neuber analysis under predicts the measured fatigue life by as much as 67% at large strains, and becomes a better predictor of life as the applied strains decrease. The elastic Neubers analysis also under predicts the measured fatigue lives by 45% at large applied strains, but seems to accurately predict lives at reversals to failure greater than 100. The fracture mechanics approach assumes elastic stresses at the crack tip, and predicts lives within 30% over the full range of strains investigated. The results show that the Neuber notch analysis is not as good an indicator of the low cycle fatigue behavior of A723 steels as is the fracture mechanics life prediction techniques. As the life cycles to failure decreases, the Neubers analysis predicts lives that are two to three times more conservative than those experimentally measured.

• OSTI ID: 191356
• Report Number(s): CONF-950740--; ISBN 0-7918-1337-1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPARATIVE EVALUATIONS
CRACK PROPAGATION
EXPERIMENTAL DATA
FATIGUE
SERVICE LIFE
STEELS