Journal of the Earthquake Engineering Society of Korea (한국지진공학회논문집)

Earthquake Engineering Society of Korea (한국지진공학회)
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Seismic Response Prediction of a Structure Using Experimental Modal Parameters from Impact Tests

충격시험에 의한 실험모드특성을 이용한 구조물의 지진응답 예측

  • Published : 2010.04.30
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Abstract

An in-cabinet response spectrum should be generated to perform the seismic qualification of devices and instruments mounted inside safety-related electrical equipment installed in nuclear power plants. The response spectrum is available by obtaining accurate seismic responses at the device mounting location of the cabinet. The dynamic behavior of most of electrical equipment may not be easily analyzed due to their complex mass and stiffness distributions. Considering these facts, this study proposes a procedure to estimate the seismic responses of a structure by a combination of a test and subsequent analysis. This technique firstly constructs the modal equations of the structure by using the experiment modal parameters obtained from the impact test. Then the seismic responses of the structure may be calculated by a mode superposition method. A simple steel frame structure was fabricated as a specimen for the validation of the proposed method. The seismic responses of the specimen were estimated by using the proposed technique and compared with the measurements obtained from the shaking table tests. The study results show that it is possible to accurately estimate the seismic response of the structure by using the experimental modal parameters obtained from the impact test.

원자력발전소에 설치되는 주요 전기기기들의 내부 부품을 내진검증하기 위해서는 캐비닛내부응답스펙트럼이 필요하고, 이는 캐비닛의 각 위치에서 정확한 지진응답을 구한 후에 생성이 가능하다. 반면에 대부분의 전기기기는 질량과 강성 분포가 복잡하기 때문에 해석적 방법에 의해 동적 분석을 수행하는 것이 어렵다. 이러한 여건을 감안하여 이 연구에서는 해석과 시험을 조합하여 기기의 지진응답을 예측하는 간편한 절차를 제안하였다. 제안된 절차는 먼저 충격시험을 통하여 규명된 실험모드특성을 이용하여 독립된 모드방정식을 구성하고, 이로부터 모드응답을 계산한 다음, 각 모드응답을 중첩함으로써 구조물의 지진응답을 예측한다. 제안된 절차의 신뢰성을 검증하기 위해서, 별도로 제작된 단순 강재 프레임 시편에 제안된 절차를 적용하여 지진응답을 예측하고, 이를 실제 진동대시험을 통하여 계측한 결과와 비교하였다. 이 연구를 통하여 충격시험에 의해 얻어진 실험모드특성을 이용하여 구조물의 지진응답을 비교적 정확하게 예측할 수 있음을 확인하였다.

Keywords

References

  1. ANSI/IEEE, IEEE Recommended Practices for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations, Std.-344, The Institute of Electrical and Electronics Engineers, 2004.
  2. Djordjevic, W., O'Sullivan, J.J., Guidelines for Development of In-Cabinet Amplified Response Spectra for Electrical Benchboards and Panels, EPRI NP-7146s-M, Prepared by Stevenson & Associates, Inc., 1990.
  3. Bandyopadhyay, K.K. and Hofmayer, C.H., Seismic Fragility of Nuclear Power Plant Components (Phase I), NUREG/CR-4659, US Nuclear Regulatory commission, 1986.
  4. T.Y. Chang, Seismic qualification of equipment in operating nuclear power plants, USNRC, NUREG-1030, 1985.
  5. Gupta, A., Yang, S.K. and Gupta, A.K., “Ritz Vector Approach for Evaluating Incabinet Response Spectra,” Nuclear Engineering and Design, Vol. 190, 255-272, 1999. https://doi.org/10.1016/S0029-5493(99)00076-X
  6. Gupta, A., and Yang, J., “Modified Ritz Vector Approach for Dynamic Properties of Electrical Cabinets and Control Panels,” Nuclear Engineering and Design, Vol. 217, 49-62, 2002. https://doi.org/10.1016/S0029-5493(02)00133-4
  7. Yang, J., and Gupta, A., “INCABS: A Computer Program for Evaluating Incabinet Spectra,” Paper #2072, Transactions, SMiRT 16, Washinton DC, August 2001.
  8. Rustogi, S., and Gupta, A., “Modeling the Dynamic Behavior of Electrical Cabinets and Control Panels: Experimental and Analytical Results,” J. Structural Engineering, Vol. 130, No. 3, 511-519, 2004. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:3(511)
  9. 구기영, 취진타오, 조성국, 김두기, “진동시험을 이용한 원자력발전소 캐비닛구조의 지진응답예측 기법,” 한국지진공학회, 제12권, 제5호, 57-63, 2008.
  10. 김두기, 구조동역학, 제 2판, 구미서관, 2009.
  11. MATLAB, The Language of Technical Computing, Version 7.0, Mathworks, 2004.
  12. Richardson, M. and Schwarz, B., “Modal Parameter Estimation form Operating Data,” Sound and Vibration, January 2003.
  13. Richardson, M., “Modal Mass, Stiffness and Damping,” Vibrant Technology, Inc., Jamestown, CA, January, 2000.
  14. STAR User's Guide, Spectral Dynamics, Inc., 1996.
  15. 조성국, 조양희, 소기환, “실험모드분석에 의한 3층 프레임 시편의 지진응답 예측,” 한국지진공학회 2010 춘계학술발표회 논문집, 강원대학교, 2010. 3. 19.
  16. 3-series/NVGate Reference Manual, OROS, 2006.