Journal of Mechanical Science and Technology

The Korean Society of Mechanical Engineers (대한기계학회)
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Sensitivity Analysis of Anti-resonance Frequency for Vibration Test Control of a Fixture

  • Jeong, Weui-Bong (Department of Mechanical Engineering, Pusan National University) ;
  • Yoo, Wan-Suk (Department of Mechanical Engineering, Pusan National University) ;
  • Kim, Jun-Yeop (The Environment Test Lab., Agency for Defense Development)
  • Published : 2003.11.01
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Abstract

The test specimen in environmental vibration test is connected to the fixture through several attachment points. The forces generated by the shaker must be transmitted equally to all attachment points. The forces transmitted to attachment points, however, are different because of the flexural vibration of the fixture. The variations of the transmitted force cause the under-test, especially at anti-resonance frequencies, in vibration test control. Anti-resonance frequencies at the attachment points of the fixture must be same in order to avoid the under-test in vibration test control. The structural modification of the fixture is needed so that anti-resonance frequencies at attachment points have the same value. In this paper, the method to calculate the anti-resonance frequencies and those sensitivities is presented. This sensitivity analysis is applied to the structural modification of the fixture excited at multi-points by the shaker. The antiresonance frequencies at the attachment points of the fixture can have the same value after structural modification, and the under-test in the vibration test control can be removed. Several computer simulations show that the proposed method can remove the under-tests, which are not removed in conventional vibration test control.

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References

  1. Afolabi, D., 1987, 'An Anti-resonance Technique for Detecting Structural Damage,' Proceedings of 5th IMAC, pp. 491-495
  2. Berkman, H. R., 1968, 'Control Point Averaging for Large Specimen Vibration,' Shock and Vibration Bulletin, Vol. 37, pp. 75-88
  3. deSilva, C. W., Henning, S. J. and Brown, J. D., 1993, 'Random Testing with Digital Control-Application in the Distribution Qualification of Micro Computers,' Shock and Vibration Bulletin, Vol. 62, pp. 101-109
  4. He, J. and Li, Y. Q., 1995, 'Relocation of Anti-Resonances of Vibratory System by Local Structural Change,' Int. J. of Analytical and Experimental Modal Analysis, Vol. 10, No. 4, pp. 224-235
  5. Kajiwara, I. and Nagamatsu, A., 1993, 'Optimal Design of Optical Pick-up by Elimination of Resonance Peaks,' Jr. of Vibration and Acoustics, Vol. 115, pp. 377-383 https://doi.org/10.1115/1.2930360
  6. Kim, J. Y., Chang, S. J., Kim, D. Y. and Jeong, W. B., 1996, 'A Study on the Determination of Optimal Reference Spectrum for Random Vibration Control in Environmental Vibration Test,' KSME Journal, Vol. 10, No. 2, pp. 246-254 https://doi.org/10.1007/BF02953663
  7. Nagamatsu, A., 1986, Modal Analysis, Baifukan. Japan
  8. Scharton, T. D., 1969, 'Development of Impedance Simulation Fixture for Spacecraft Vibration Tests,' NASA CR1351
  9. Shepard, G. D., 1985, 'On Anti-resonance, with Application to Control of Structurals,' Proceedings of 3rd IMAC, pp. 523-526
  10. Shurtleff, W. W., 1967, 'Averaging Fundamental Vibration Control Signals: A Theoretical Study,' Shock and Vibration Bulletin, Vol. 36, pp. 139-146