쇄빙선 강재의 내충격 특성에 관한 실험적 연구: 제1부 강재 특성
Study on Crashworthiness of Icebreaker Steel: Part I Steel Properties
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This paper presents a study on the crashworthiness of the scaled-down stiffened panels used on a Korean icebreaker. In order to validate the crashworthiness of the panels, this paper provides various mechanical properties such as the results of a CVN test, quasi-static tensile test, and high-speed tensile test at arctic temperatures. Two types of steels (EH32 and FH32) were chosen for the material tests. CVN tests revealed that the two steels were equivalent up to -60℃ in terms of their impact energy absorption capacity. However, the toughness of FH32 was significantly superior to that of EH32. EH32 showed slightly higher flow stresses at all temperature levels compared to FH32. The improvement ratios of the yield strengths, tensile strengths, plastic hardening exponents, etc. for FH32, which were obtained from quasi-static tensile tests, showed an apparent ascending tendency with a decrease in temperature. Dynamic tensile test results were obtained for the two temperatures levels of 20℃ and –60℃ with two plastic strain rate levels of 1 s-1 and 100 s-1. A closed form empirical formula proposed by Choung et al. (2011; 2013) was shown to be effective at predicting the flow stress increase due to a strain rate increase.
Abstract
This paper presents a study on the crashworthiness of the scaled-down stiffened panels used on a Korean icebreaker. In order to validate the crashworthiness of the panels, this paper provides various mechanical properties such as the results of a CVN test, quasi-static tensile test, and high-speed tensile test at arctic temperatures. Two types of steels (EH32 and FH32) were chosen for the material tests. CVN tests revealed that the two steels were equivalent up to -60℃ in terms of their impact energy absorption capacity. However, the toughness of FH32 was significantly superior to that of EH32. EH32 showed slightly higher flow stresses at all temperature levels compared to FH32. The improvement ratios of the yield strengths, tensile strengths, plastic hardening exponents, etc. for FH32, which were obtained from quasi-static tensile tests, showed an apparent ascending tendency with a decrease in temperature. Dynamic tensile test results were obtained for the two temperatures levels of 20℃ and –60℃ with two plastic strain rate levels of 1 s-1 and 100 s-1. A closed form empirical formula proposed by Choung et al. (2011; 2013) was shown to be effective at predicting the flow stress increase due to a strain rate increase.
참고문헌 (24)
- American Society of Materials International (ASM), "ASM Handbook Volume 8 Mechanical Testing and Evaluation" (2000), ASM
- American Society for Testing and Materials (ASTM), "E646-07e1 Standard Test Method for Tensile Strain-Hardening Exponents (n -Values) of Metallic Sheet Materials", ~ (2007)
- American Society for Testing and Materials (ASTM), "E23-12c Standard Test Methods for Notched Bar Impact Testing of Metallic Materials", ~ (2012)
- American Society for Testing and Materials (ASTM), "A131M-14 Standard Specification for Structural Steel for Ships", ~ (2014)
- American Society for Testing and Materials (ASTM), "E8M-15a Standard Test Methods for Tension Testing of Metallic Materials", ~ (2015)
- Min, D.K, "On the Plastic and Fracture Damage of Ice Class Vessel Structures Subjected to Impact Loadings", Ph.D, pp.2011
- "YS 500N/mm2 High Strength Steel for Offshore Structures with Good CTOD Properties at Welded Joints" (2004)[URL]
- Terada, Y, "High Strength UOE Pipe With Excellent CTOD Properties And Deformability", Proceedings of 22nd International Conference on Offshore Mechanics and Arctic Engineering 2013 (OMAE 2003) (2003)
- Det Norske Veritas(DNV), "Offshore Standard DNV-OS-B101 Metallic Materials", ~ (2009)
- Choung, J, "Dynamic Hardening Behaviors of Various Marine Structural Steels Considering Dependencies on Strain Rate and Temperature", Marine Structures, 32, pp.49~67 (2013)
- 정준모, "조선 해양 구조물용 강재의 소성 및 파단 특성 V: 온도 의존성을 고려한 변형률 속도에 관한 실험적 연구", 한국해양공학회지, 25(3), pp.74~85 (2011), 한국해양공학회
- 정준모, "중변형률 속도 유동응력 확보를 위한 고속 인장 실험기 설계", 한국해양공학회지, 29(1), pp.34~44 (2015), 한국해양공학회
- Strain Hardening and Strain Rate Effects in the Loading of Cantilever Beams, "Cowper, G", Brown Univ. Applied Mathematics, 28~, pp.Report No. 28 (1957)
- Fitoussi, J, "Experimental Methodology for High Strain-rates Tensile Behavior Analysis of Polymer Matrix Composites", Composites Science and Technology, 65, pp.2174~2188 (2005)
- International Organization for Standardization(ISO), "ISO 19906:2010 Petroleum and Natural Gas Industries -- Arctic Offshore Structures", ~ (2010)
- International Organization for Standardization(ISO), "ISO 19902 : 2007 Petroleum and Natural Gas Industries--Fixed Steel Offshore Structures", ~ (2007)
- Othman, R, "A Modified Servo-hydraulic Machine for Testing at Intermediate Strain Rates", International Journal of Impact Engineering, 36, pp.460~467 (2009)
- "The Prospects and Challenges for Arctic Oil Development" (2014)[URL]
- Schobig, M, "Mechanical Behavior of Glass-fiber Reinforced Thermoplastic Materials under High Strain Rates", Polymer Testing, 27, pp.893~900 (2008)
- Silva, F, "High Speed Tensile Behavior of Sisal Fiber Cement Composites", Materials Science and Engineering A, 527, pp.544~552 (2010)
- "Opportunities and Challenges for Arctice Oil and Gas Development" (2015)[URL]
- Zhu, D, "Modal Analysis of a Servo-Hydraulic High Speed Machine and Its Application to Dynamic Tensile Testing at an Intermediate Strain Rate", Experimental Mechanics, 51(8), pp.1347~1363 (2010)
- Zhu, D, "Characterization of Dynamic Tensile Testing Using Aluminum Alloy 6061-T6 at Intermediate Strain Rates", Journal of Engineering Mechanics, 137, pp.669~679 (2011)
- Zrida, M., "High-speed Tensile Tests on a Polypropylene Material", Polymer Testing, 29, pp.685~692 (2010)