Retardation Behavior and Crack-Through-Thickness of a Surface-cracked Specimen under Cyclic Load |
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피로하중을 받는 표면균열재의 관통거동 및 지연거동 |
남기우 |
부산수산대학교 |
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© 1991 The Korean Society of Ocean Engineers
Open access / Under a Creative Commons License
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Keywords:
Fatigue Life, Retardation Behavior, Through Thickness, Stress Intensity Factor, Retardation Factor |
핵심용어:
피로수명, 지연거동, 두께관통, 응력확대계수, 지연계수 |
Abstract |
Fatigue life and retardtion behavior after through-thickness were examined experimentally by using a CT specimen and surface-cracked specimen. The material used was 3% Ni-Cr-Mo steel. The fatigue crack shape before through-thickness is almost semicircular, and the measured aspect ratio is larger than the value obtained by calculation using the K value proposed by Newman-Raju. It is found that the crack growth behavior on the back side after through-ghickness is unique and can be divided into three stages a, b and c. A retardation parameter has been used successfully to predict the growth of cracks in specimen, and in this time, retardation factor is 4.3. By using the crack propagation rule considering on retardation state and the K value proposed by the authors, the remarkable crack growth behavior and the change in crack shape can be evaluated quantitatively. |
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