Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Investigation of Error Factors from an Impact Hammer Test for Developing a Statistic Based Technique for Model Updating

통계 기반 모델 개선을 위한 임팩트 해머 실험의 오차 요인 분석

  • Lee, Su (Division of Mechanical Engineering, Ajou Univ.) ;
  • Lee, Jin Woo (Division of Mechanical Engineering, Ajou Univ.)
  • 이수 (아주대학교 기계공학과) ;
  • 이진우 (아주대학교 기계공학과)
  • Received : 2015.09.17
  • Accepted : 2015.11.16
  • Published : 2016.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this work, experimental errors from an impact hammer test were investigated to develop a statistic-based technique for updating a finite element model. Digital signal processing was analyzed by using theoretical models and experiments when errors occurred during the experimental procedure. First, the duration time and peak level of the excitation signal, the stiffness and position of elastic springs connecting the specimen as well as the support, position and mass of the accelerometer were considered as error factors during the experiment. Then the picket fence effect, leakage, and exponential window function were considered as candidate error factors during the digital signal processing. Finally, methods to reduce errors are suggested.

본 논문에서는 통계적인 기법을 기반으로 유한 요소 모델을 개선하기 위해 수행되는 임팩트 해머 실험에서 발생할 수 있는 오차 요인을 분석하고, 오차를 줄일 수 있는 방안을 제시한다. 먼저, 이론 모델과 실험을 통해, 실험 과정과 측정된 신호를 후처리 하는 과정에서 발생할 수 있는 오차 요인을 파악한다. 실험 오차 요인으로 가진력의 지속 시간과 크기, 시편을 지지대와 연결하는 고무줄의 강성과 위치, 응답 신호를 측정하기 위해 시편에 부착하는 가속도계의 위치와 질량을 고려하고, 이에 따른 고유 모드와 고유 주파수의 변화를 살펴본다. 그리고, 디지털 신호 처리 과정에서는 말뚝 울타리 효과, 누설, 지수창 함수 사용에 의한 오차를 살펴보고, 이런 오차를 줄일 수 있는 방법을 제시한다.

Keywords

References

  1. Unlusoy, L., Sahin, M. and Yaman, Y., 2012, "Verification of a Finite Element Model of an Unmanned Aerial Vehicle Wing Torque Box via Experimental Modal Testing," ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis.
  2. Angeli, P., Barazza, F. and Blanchini, F., 2010, "Natural Frequency Intervals for Vibrating Systems with Polytopic Uncertainty," Journal of Sound and Vibration, Vol. 329, Issue.7, pp. 944-959. https://doi.org/10.1016/j.jsv.2009.10.014
  3. Gao, W., 2007, "Natural Frequency and Mode Shape Analysis of Structures with Uncertainty," Mechanical Systems and Signal Processing, Vol. 21, No. 1, pp.24-39. https://doi.org/10.1016/j.ymssp.2006.05.007
  4. Carne, T. G. and Dohrmann, C, R., 1998, "Support Conditions, Their Effect on Measured Modal Parameters," Proceedings of the 16th International Modal Analysis Conference.
  5. Baldanzini, N. and Pierini, M., 2002, "An Assessment of Transducer Mass Loading Effects on The Parameters of An Experimental Statistical Energy Analysis (SEA) Model," Mechanical Systems and Signal Processing, Vol.16, No.5, pp.885-903. https://doi.org/10.1006/mssp.2002.1485
  6. Kotambkar, M., S., 2014, "Effect of Mass Attachment of Natural Frequency of Free-Free Beam Analytical, Numerical and Experimental Investigation," International Journal of Advanced Engineering Research and Studies, Vol. (III/IV), pp. 102-115.
  7. Baharin, N., H. and Rahman, R. A., 2009, "Effect of Accelerometer Mass on Thin Plate Vibration," Jurnal Mekanikal, No.29 pp. 100-111.
  8. Ingber, M. S., Pate, A. L. and Salazar, J. M., 1992, "Vibration of a Clamped Plate with Concentrated Mass and Spring Attachments, Journal of Sound and Vibration," Vol.153, No.1, pp.143-166. https://doi.org/10.1016/0022-460X(92)90633-9
  9. Chiba, M. and Sugimoto, T., 2003, "Vibration Characteristics of a Cantilever Plate with Attached Spring-Mass System," Journal of Sound and Vibration, Vol. 260, Issue.2, pp. 237-263. https://doi.org/10.1016/S0022-460X(02)00921-5
  10. Koruk, H. and Sanliturk, K. Y., 2011, "Kamping Uncertainty Due to Noise and Exponential Windowing," Journal of Sound and Vibration, Vol. 330, Issue. 23, pp. 5690-5706. https://doi.org/10.1016/j.jsv.2011.07.006
  11. Ahn, S. J. and Jeong, W. B., 2003, "FRF Distortion Caused by Exponential Window Function on Impact Hammer Testing and Its Solution," Transactions of KSNV, Vol. 13, No. 5, pp. 334-340.
  12. Tondreau, G. and Deraemaeker, A., 2014, "Numerical and Experimental Analysis of Uncertainty on Modal Parameters Estimated with The Stochastic Subspace Method," Journal of Sound and Vibration, Vol. 333, No. 18, pp. 4376-4401. https://doi.org/10.1016/j.jsv.2014.04.039
  13. Griffith, D., T. and Carne, T., G., 2007, "Experimental Uncertainty Quantification of Modal Test Data," 25th International Modal Analysis Conference.
  14. Ashory, M., R., 1998, "Correction of Mass-Loading Effects of Transducers and Suspension Effects in Modal Testing," SPIE Proceedings Series Society of Photo Optical Instrumentation Engineers.
  15. Ashory, M., R., 2002, "Assessment of the Mass- Loading Effects of Accelerometers in Modal Testing," SPIE Proceedings Series Society of Photo-Optical Instrumentation Engineers.
  16. Hosoya, N., Yaginuma, S., Onodera, H. and Yoshimura, T., 2015, "Estimation of the Auto Frequency Response Function at Unexcited Points Using Dummy Masses," Journal of Sound and Vibration Vol. 337, pp. 14-27. https://doi.org/10.1016/j.jsv.2014.09.033
  17. Lee, J., Y., 2000, "Prediction of Modified Structural Natural Frequencies and Modes Using Iterative Sensitivity Coefficient," Journal of KSMTE, Vol. 9, No. 5, pp. 40-46.
  18. Lee, J., Y., 2002, "A Structural Eigen derivative Analysis by Modification of Design Parameter," Trans of Korean Soc. Mech. Eng. A, Vol. 26, No. 4, pp. 739-744. https://doi.org/10.3795/KSME-A.2002.26.4.739
  19. Lee, J., Y., 2015, "Model Updating in Small Structural Dynamics Model by Elimination of Mass Loading Effect of Accelerometer," Transactions of KSNV, Vol. 25, No. 1, pp. 40-47.
  20. Silva, J. M.M., Maia, N. M.M. and Ribeiro, A.M. R., 2000, "Cancellation of Mass-Loading Effects of Transducers and Evaluation of Unmeasured Frequency Response Functions," Journal of Sound and Vibration, Vol. 236, No. 5, pp. 761-779. https://doi.org/10.1006/jsvi.1999.2993