A study on the growth behaviors of surface fatigue crack initiated from a small-surface defect of 2024-T3 and brass |
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2024-T3 및 황동의 작은 표면결함재의 피로균열 성장특성에 관한 연구 |
서창민,오명석 |
경북대학교 기계공학부,영남전문대학 기계과 |
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© 1996 The Korean Society of Ocean Engineers
Open access / Under a Creative Commons License
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Keywords:
Surface Crack, Stress Intensity Factor, Crack Growth Rate, Cycle Ratio, Total Strain Intensity Factor |
핵심용어:
표면균열, 응력확대계수, 균열성장율, 반복수, 전스트레인 확대계수 |
Abstract |
In this paper, rotating bending fatigue tests have been carried out to investigate the growth behabiors of surface fatigue crack initiated from a small artificial surface defect, that might exist in real structures, on 2024-T3 and 6:4 brass. The test results are analysed in the viewpoints of both strength of materials and fracture mechanics, it can be concluded as follows. The effect of a small artificial surface defect upon the fatigue strength is very large. The sensitivity of 2024-T3 on the defect is higher than that of 6:4 brass. The growth behavior of the surface fatigue crack of 2024-T3 is different from that of 6:4 brass. The growth rate of the surface fatigue crack of 2024-T3 is considerably rapid in the early stage of the fatigue life and apt to decrease in the later stage. It was impossible to establish a unifying approach in the analysis of crack growth begabior of 2024-T3 and 6:4 brass using the maximum stress intensity factor because of their dependence on stress level. But if the elastic strain and cyclic total strain intensity factor range were applied to obtain the growth rate of surface fatigue cracks of the materials, the data were found to be nearly coincided. |
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