Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
권호 표지
DOI QR코드

DOI QR Code

Nonproportional viscous damping matrix identification using frequency response functions

주파수 응답 데이터를 이용한 비비례 점성감쇠행렬 추정

  • Min, Cheon-Hong (Technology Center for Offshore Plant Industries, Korea Research Institute of Ships & Ocean Engineering) ;
  • Kim, Hyung-Woo (Technology Center for Offshore Plant Industries, Korea Research Institute of Ships & Ocean Engineering)
  • Received : 2016.01.07
  • Accepted : 2016.04.18
  • Published : 2016.05.31
Download PDF
⟨ Previous Next ⟩

Abstract

Accurate identification of damping matrix in structures is very important for predicting vibration responses and estimating parameters or other characteristics affected by energy dissipation. In this paper, damping matrix identification method that use normal frequency response functions, which were estimated from complex frequency response functions, is proposed. The complex frequency response functions were obtained from the experimental data of the structure. The nonproportional damping matrix was identified through the proposed method. Two numerical examples (lumped-mass model and cantilever beam model) were considered to verify the performance of the proposed method. As a result, the damping matrix of the nonproportional system was accurately identified.

감쇠구조물의 해석을 위해서는 정확한 감쇠모델을 구성하는 것이 중요하지만, 감쇠특성을 모델링 하는 것은 매우 어려운 일이다. 부정확한 감쇠 모델링에서 기인하는 오차는 진동 소음 문제 및 구조물 안전 평가 등에 많은 어려움을 주고 있다. 본 연구에서는 주파수 응답함수를 이용한 비비례 점성감쇠행렬 추정기법을 제시하였다. 복소 주파수 응답함수는 구조물의 실험데이터로부터 계측되며, 정상상태 주파수 응답함수는 계측된 복소 주파수 응답함수로부터 추정된다. 제안된 기법을 통해 비비례 점성감쇠 행렬을 추정하였으며, 두 가지 수치 예제(집중질량 모델과 외팔보)를 통해 제시된 기법을 검토하였다. 결과적으로 두 가지 예제 모두에서 비비례 점성감쇠 행렬을 정확히 추정할 수 있었다.

Keywords

References

  1. G. M. Lee, Y. H. Ju, and M. S. Park, "Comparison of damping matrix estimation methods for model updating," Transactions of the Korean Society for Noise and Vibration Engineering, vol. 20, no. 10, pp. 923-930, 2010 (in Korean). https://doi.org/10.5050/KSNVE.2010.20.10.923
  2. S. C. Park, Y. B. Park, K. I. Park, H. K. Je, and G. J. Yi, "Identification of damping matrix for a steel bar by the genetic algorithm," Journal of the Korean Society of Marine Engineering, vol. 35, no. 2, pp. 271-277, 2011 (in Korean). https://doi.org/10.5916/jkosme.2011.35.2.271
  3. C. H. Min, H. I. Park, and S. Y. Park, "Direct identification of non-proportional modal damping matrix for lumped mass system using modal parameters," Journal of Mechanical Science and Technology, vol. 26, no. 4, pp. 993-1002, 2012. https://doi.org/10.1007/s12206-012-0221-1
  4. J. H. Lee and J. Kim, "Development and validation of a new experimental method to identify damping matrices of a dynamic system," Journal of Sound and Vibration, vol. 246, no. 3, pp. 505-524, 2001. https://doi.org/10.1006/jsvi.2001.3670
  5. K. S. Kim, Y. J. Kang, and J. Yoo, "Structural parameters identification using improved normal frequency response function method," Mechanical Systems and Signal Processing, vol. 22, pp. 1858-1868, 2008. https://doi.org/10.1016/j.ymssp.2008.02.001
  6. S. Pradhan and S. V. Modak, "A method for damping matrix identification using frequency response data," Mechanical Systems and Signal Processing, vol. 33, pp. 69-82, 2012. https://doi.org/10.1016/j.ymssp.2012.07.002
  7. C. H. Min, H. W. Kim, C. H. Lee, S. Hong, J. S. Choi, and T. K. Yeu, "Identification of a nonproportional damping matrix using the finite element model updating," Journal of Ocean Engineering and Technology, vol. 26, no. 4, pp. 86-91, 2012 (in Korean). https://doi.org/10.5574/KSOE.2012.26.4.086
  8. V. Arora, "Structural damping identification method using normal FRFs," International Journal of Solids and Structures, vol. 51, pp. 133-143, 2014. https://doi.org/10.1016/j.ijsolstr.2013.09.017
  9. S. Y. Chen, M. S. Ju, and Y. G. Tsuei, "Estimation of mass, stiffness and damping matrices from frequency response functions," Journal of Vibration and Acoustics, vol. 118, no. 1, pp. 78-82, 1996. https://doi.org/10.1115/1.2889638
  10. M. I. Friswell, S. D. Garvey, and J. E. T. Penny, "Model reduction using dynamic and iterated IRS techniques," Journal of Sound and Vibration, vol. 186, no. 2, pp. 311-323, 1995. https://doi.org/10.1006/jsvi.1995.0451