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Plasticity and Fracture Behaviors of Marine Structural Steel, Part II: Theoretical Backgrounds of Fracture

조선 해양 구조물용 강재의 소성 및 파단 특성 II: 파단의 이론적 배경

  • Choung, Joon-Mo (Dep't of Naval Architecture and Ocean Engineering, Inha University) ;
  • Shim, Chun-Sik (Dep't of Naval Architecture and Marine Engineering, Mokpo National University) ;
  • Kim, Kyung-Su (Dep't of Naval Architecture and Ocean Engineering, Inha University)
  • 정준모 (인하대학교 조선해양공학과) ;
  • 심천식 (국립목포대학교 조선공학과) ;
  • 김경수 (인하대학교 조선해양공학과)
  • Received : 2011.02.14
  • Accepted : 2011.04.22
  • Published : 2011.04.30

Abstract

The main goal of this paper is to provide the theoretical background for the fracture phenomena in marine structural steels. In this paper, various fracture criteria are theoretically investigated: shear failure criteria with constant failure strain and stress triaxiality-dependent failure strain (piecewise failure and Johnson-Cook criteria), forming limit curve failure criterion, micromechanical porosity failure criterion, and continuum damage mechanics failure criterion. It is obvious that stress triaxiality is a very important index to determine the failure phenomenon for ductile materials. Assuming a piecewise failure strain curve as a function of stress triaxiality, the numerical results coincide well with the test results for smooth and notched specimens, where low and high stress triaxialities are observed. Therefore, it is proved that a failure criterion with reliable material constants presents a plastic deformation process, as well as fracture initiation and evolution.

Keywords

Stress triaxiality;Fracture strain(Failure strain);Shear failure;Porosity;Principal strain;Damage

References

  1. AbuBakar, A. and Dow, R.S. (2010). "Simulation of Grounding Damage using the Finite Element Method", Proceedings of 5th International Conference on Collision and Grounding of Ships (ICCGS 2010), pp 208-216.
  2. Bonora, N. (1997). "A Nonlinear CDM Model for Ductile Failure", Engineering Fracture Mechanics, Vol 58, pp 11-28. https://doi.org/10.1016/S0013-7944(97)00074-X
  3. Bressan, J.D. and Williams, J.A. (1983). "The Use of a Shear Instability Criterion to Predict Local Necking in Sheet Metal Deformation", International Journal of Mechanical Sciences, Vol 25, pp 155-168. https://doi.org/10.1016/0020-7403(83)90089-9
  4. Choung, J., Shim, C.S. and Kim, K.S. (2011). "Plasticity and Fracture Behaviors of a Marine Structural Steel, Part I: Theoretical Backgrounds of Strain Hardening and Rate Hardening", Journal of Ocean Engineering and Technology (to be published).
  5. Choung, J. (2009a). "Comparative Studies of Fracture Models for Marine Structural Steels", Ocean Engineering, Vol 36, pp 1164-1174. https://doi.org/10.1016/j.oceaneng.2009.08.003
  6. Choung, J. (2009b). "Micromechanical Damage Modeling and Simulation of Punch Test", Ocean Engineering, Vol 36, pp 1158-1163. https://doi.org/10.1016/j.oceaneng.2009.08.004
  7. Choung, J. and Cho, S.R. (2008). "Study on True Stress Correction from Tensile Tests", Journal of Mechanical Science and Technology, Vol 22, pp 1039-1051. https://doi.org/10.1007/s12206-008-0302-3
  8. Choung, J., Cho, S.R. and Yoon, K.Y. (2007). "On Comparative Studies of Fracture Models for Shipbuilding and Offshore Structural Steels", Proceedings of 4th International Conference on Collision and Grounding of Ships (ICCGS 2007), pp 177-185.
  9. Gurson, A. (1977). "Continuum Theory of Ductile Rupture by Void Nucleation and Growth: Part 1 -Yield Criteria and Flow Rules for Porous Ductile Media", ASME J. Eng. Mat. and Tech., Vol 99, pp 2-15. https://doi.org/10.1115/1.3443401
  10. Health and Safety Executive (2001). Offshore Technology Report OTO 2001/020-Elevated Temperature and High Strain Rate Properties of Offshore Steels.
  11. Jie, M., Cheng, C.H., Chan, L.C. and Chow, C.L. (2009). "Forming Limit Diagrams of Strain-rate-dependent Sheet Metals", International Journal of Mechanical Sciences, Vol 51, No 4, pp 269-275. https://doi.org/10.1016/j.ijmecsci.2009.01.007
  12. Johnson, G.R. and Cook, W.H. (1985). "Fracture Characteristics of Three Metals Subjected to Various Strain, Strain Rates Temperatures and Pressures", Engineering Fracture Mechanics, Vol 21, No 1, pp 31-48. https://doi.org/10.1016/0013-7944(85)90052-9
  13. Lehmann, E. and Yu, X. (1998). "On Ductile Rupture Criteria for Structural Tear in the Case of Ship Collision and Grounding", Proceedings of the 7th International Symposium on Practical Design of Ships and Mobile Units, pp 141-147.
  14. Lemaitre, J. (1992). A Course on Damage Mechanics. Springer-Velac.
  15. Nemat-Nasser, S. and Guo, W.G. (2003). "Thermomechanical Response of DH-36 Structural Steel over a Wide Range of Strain Rates and Temperature", Mech. Mat., Vol 35, pp 1023-1047. https://doi.org/10.1016/S0167-6636(02)00323-X
  16. Tornqvist, R. (2003). Design of Crashworthy Ship Structures. Technical University of Denmark, Ph.D Thesis.
  17. Tvergaard, V. (1981). "Influence of Voids on Shear Band Instabilities under Plane Strain Condition", Int. J. Fract. Mech., Vol 17, pp 389-407. https://doi.org/10.1007/BF00036191
  18. Tvergaard, V. and Needleman, A. (1984). "Analysis of the Cup-Cone Fracture in a Round Tensile Bar", Acta Metallurgica, Vol 32, pp 157-169. https://doi.org/10.1016/0001-6160(84)90213-X
  19. Urban, J. (2003). Crushing and Fracture of Lightweight Structures. Technical University of Denmark, Ph.D Thesis.
  20. Zhu, L. and Atkins, A.G. (1998). "Failure Criteria for Ship Collision and Grounding", Proceedings of the 7th International Symposium on Practical Design of Ships and Mobile Units, pp 141-147.

Cited by

  1. On the Fracture of Polar Class Vessel Structures Subjected to Lateral Impact Loads vol.49, pp.4, 2012, https://doi.org/10.3744/SNAK.2012.49.4.281
  2. Formulation of Failure Strain according to Average Stress Triaxiality of Low Temperature High Strength Steel (EH36) vol.27, pp.2, 2013, https://doi.org/10.5574/KSOE.2013.27.2.019