Journal of the Korean Society for Precision Engineering (한국정밀공학회지)
- Volume 9 Issue 1
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- Pages.106-117
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- 1992
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- 1225-9071(pISSN)
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- 2287-8769(eISSN)
A Study on Physically small Surface Fatigue Crack Growth Behavior in 7075-T651 Aluminum Alloy
7075-T651 AI 합금에 있어서 물리적 미소 표면 피로균열 성장거동에 관한 연구
- Sin, Yong-Seung (Dept.of Mechanical Engineering, Seoul National University of Technology) ;
- Seo, Seong-Won (Dept.of Mechanical Engineering, Seoul National University of Technology) ;
- Yu, Heon-Il (School of Mechanical Design engineering, Kookmin University)
- Published : 1992.03.01
Abstract
In this study, the propagation behaviour and the closure phenomena of physically small surface cracks were investigated by the techinque of the Kikukawa-unloading elastic compliance method using a back face strain gage. The surface cracks initiated and propagated from notched specimens under constant amplitude bending load. The crack shape (aspect ratio) with approximately semi-circular at the early stage was changed to semi-elliptical as the cracks grew larger. The crack depth (a) could be expressed uniquenly by the crack length (c). The dependence of the crack propagation rate on the stress ratio R was strongly related in the lower
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