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Analytical Evaluations of the Retrofit Performances of Concrete Wall Structures Subjected to Blast Load

폭발하중을 받는 콘크리트 벽체 구조물의 보강 성능에 대한 해석적 분석

  • Kim, Ho-Jin (School of Civil and Environmental Engineering, Yonsei University) ;
  • Nam, Jin-Won (School of Civil and Environmental Engineering, Yonsei University) ;
  • Kim, Sung-Bae (School of Civil and Environmental Engineering, Yonsei University) ;
  • Kim, Jang-Ho (School of Civil and Environmental Engineering, Yonsei University) ;
  • Byun, Keun-Joo (School of Civil and Environmental Engineering, Yonsei University)
  • 김호진 (연세대학교 사회환경시스템공학부) ;
  • 남진원 (연세대학교 사회환경시스템공학부) ;
  • 김성배 (연세대학교 사회환경시스템공학부) ;
  • 김장호 (연세대학교 사회환경시스템공학부) ;
  • 변근주 (연세대학교 사회환경시스템공학부)
  • Published : 2007.04.30

Abstract

In case of retrofitting a concrete structure subjected to blast load by using retrofit materials such as FRP (fiber-reinforced polymer), appropriate ductility as well as raising stiffness must be obtained. But the previous approximate and simplified models, which have been generally used in the design and analysis of structures subjected to blast load, cannot accurately consider effects on retrofit materials. Problems on the accuracy and reliability of analysis results have also been pointed out. In addition, as the response of concrete and reinforcement on dynamic load is different from that on static load, it is not appropriate to use material properties defined in the previous static or quasi-static conditions to in calculating the response on the blast load. In this study, therefore, an accurate HFPB (high fidelity physics based) finite element analysis technique, which includes material models considering strength increase, and strain rate effect on blast load with very fast loading velocity, has been suggested using LS-DYNA, an explicit analysis program. Through the suggested analysis technique, the behavior on the blast load of retrofitted concrete walls using CFRP (carbon fiber-reinforced polymer) and GFRP (glass fiber-reinforced polymer) have been analyzed, and the retrofit capacity analysis has also been carried out by comparing with the analysis results of a wall without retrofit. As a result of the analysis, the retrofit capacity showing an approximate $26{\sim}28%$ reduction of maximum deflection, according to the retrofit, was confirmed, and it is judged ate suggested analysis technique can be effectively applicable in evaluating effectiveness of retrofit materials and techniques.

폭발하중을 받는 콘크리트 구조물을 섬유 복합재 등의 보강 재료를 사용하여 보강하는 경우에는 강성 증가와 함께 적절한 연성을 확보할 수 있어야 한다. 그러나, 폭발하중을 받는 구조물의 설계 및 해석에 일반적으로 사용되는 기존의 근사적이며 단순화 모델은 보강 재료에 대한 효과를 정확히 반영할 수 없을 뿐 아니라 해석 결과의 정확성 및 신뢰성에 문제가 제기되어왔다. 또한, 동적 하중에 대한 콘크리트와 철근의 응답은 정적 하중에 대한 응답과 상이하기 때문에 기존의 정적, 준정적하에서 정의된 재료물성값들을 폭발하중에 대한 응답 계산에 사용하는 것은 부적절하다. 따라서, 본 연구에서는 명시적(explicit) 해석 프로그램인 LS-DYNA를 사용하여 매우 빠른 재하속도를 갖는 폭발하중에 대하여 강도 증진 및 변형률 속도 효과가 반영된 재료 모델을 포함하고 있는 정밀 HFPB(high fidelity physics based) 유한요소해석 기법을 제시하였다. 제시된 해석적 기법을 통하여 탄소섬유 복합재와 유리섬유 복합재를 사용하여 보강된 콘크리트 벽체의 폭발하중에 대한 거동을 해석하였으며, 이를 보강하지 않은 벽체의 해석 결과와 비교함으로써 보강 성능 분석을 실시하였다. 해석 결과 보강에 따른 최대 처짐이 약 $26{\sim}28%$ 감소하는 보강 성능을 확인하였으며, 제안된 해석 기법이 보강 재료와 보강 기법의 유효성을 평가하는데 효과적으로 적용할 수 있을 것으로 판단된다.

Keywords

References

  1. Biggs, J. M., Introduction to Structural Dynamics, McGraw-Hill, New York, 1964, pp.3-26
  2. TM5-1300/AFR 88-2/NAVFAC P-39, Structures to Resist the Effects of Accidental Explosions, Joint Departments of the Army, Air Force and Navy Washington, DC, November, 1990, TMCD Version
  3. ASCE, Structural Design for Physical Security, State of the Practice, 1999, pp.4-1-4-48
  4. TM 5-855-1/AFPAM 32-1147/NAVFACP-1080/DAHS CWEMAN- 97, Design and Analysis of Hardened Structures to Conventional Weapons Effects, Joint Departments of the Army, Air Force, Navy and the Defense Special Weapons Agency, Washington, DC, December 1997
  5. Unified Facilities Criterion (UFC 4-010-01), DoD Minimum Antiterrorism Standards for Buildings, Washington, 31 July 2002
  6. LS-DYNA, Theoretical Manual, Hallquist, John O. (editor), Livermore Software Technology Corporation, Livermore, CA, May 1998, pp.16.8-16.11, 3.1-6.12
  7. LS-DYNA, Keyword Users Manual Version 970, Livermore Software Technology Corporation, April 2003, pp.20.l- 20.227
  8. Tavarez, F. A., Simulation of Behavior of Composite Grid Reinforced Concrete Beams Using Explicit Finite Element Method, Thesis of Master of Science, University of Wisconsin- Madison, 2001, pp.47-48
  9. Malvar, L. J., Crawford, J. E., Wesevich, J. W., and Simons, D., 'A Plasticity Concrete Material Model for DYNA3D', International Journal of Impact Engineering, Vol.19, No.9/ 10, 1997, pp.847-873 https://doi.org/10.1016/S0734-743X(97)00023-7
  10. Jones, N., Structural Aspects ofShip Collisions, Chapter II, in Structural Crashworthiness, Eds. N. Jones and T. Wierzbicki, Butterworths, London, 1983, pp.308-337
  11. Choi, H. and Krauthammer, T., 'Development of Progressive Collapse Analysis Procedure Considering Local Buckling Effects', The 1st International Conference on Design and Analysis of Protective Structures against Impact/ Impulsive/ Shock Loads (DAPSIL), Tokyo, Japan, Dec. 2003, pp.481 -488
  12. 정홍재, 섬유보강재의 특성을 고려한 콘크리트 슬래브의 폭발거동 해석, 연세대학교 석사학위논문, 2007, pp.36-69
  13. Kollar, L. P. and Springer, G. S., Mechanics of Composite Structures, Cambridge University Press, 2002, pp.14-19
  14. 남진원, 김호진, 이우철, 변근주, '폭발하중을 받는 콘크리트 벽체의 동적거동 해석', 대한토목학회 정기학술발 표대회 논문집, 2006, pp.2555-2558
  15. Byun, K. J., Nam, J. W., Kim, H. J., and Kim, S. B., 'Dynamic Analysis of Reinforced Concrete Wall under Blast Loading', Proceeding of 2nd ACF International Conference, Asian Concrete Federation, Bali, Indonesia, 20-21 November 2006, pp.180-186
  16. Belytschko, T. and Tsay, C. S., 'Explicit Algorithms for Nonlenear Dynamics of Shells', AMD-Vol.48, ASME, 1981, pp.209-231
  17. Fyfe, Tyfo${\circleR}$ SEH-51A Composit Using Tyfo${\circleR}$S Epoxy, The Fibrwrap Company, Nancy Ridge Technology Center 6310 Nancy Ridge Drive, Suite 103, San Diego, CA 92121, 2005, www.fyfeco.com
  18. Fyfe, $Tyfo^{\circleR}$ SCH-41S Composit Using $Tyfo^{\circleR}$ S Epoxy, The Fibrwrap Company, Nancy Ridge Technology Center 6310 Nancy Ridge Drive, Suite 103, San Diego, CA 92121, 2005, www.fyfeco.com
  19. 연세대학교방호기술연구센터, 고성능 섬유복합재로 보강 된 철큰콘크리트 벽체의 방폭성능 평가, 2006, pp.45-49
  20. Karagozian & Case, RC Wall Pre-test Analysis, Technical Report submitted to Yonsei PROSTEC, Karagozian & Case, 2550 N. Hollywood Way Suite 500, Burbank, CA 91505, 2006, pp.13-67
  21. Patoary, M. K. H. and Tan, K. H., 'Blast Resistance of Prototype In-Build Masonry Walls Strengthened with FRP Systems', 6th International Symposium on FRP Reinforcement for Concrete Structures, Singapore, July 8-10, 2003, Vol.2, pp.1189-1198

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