Power delivered to mechanical systems by random vibrations

Article type: Research Article

Authors: Edwards, Timothy S.

Affiliations: Analytical Structural Dynamics, Org.1523, Sandia National Laboratories, MS0557, P.O. Box 5800, Albuquerque, NM 87185, USA. E-mail: tsedwar@sandia.gov

Abstract: This paper develops deformational response power descriptions of multiple degree-of-freedom systems due to stationary random vibration excitation. Two new concepts are developed. The deformational response power density (DRPD) can be computed when a structure's natural frequencies and modal masses are available. The DRPD shows the spectral content of the deformational power delivered to a specific structure by the stationary, random excitation. This function can be found through a weighted windowing of the power spectrum of the input acceleration excitation. Deformational response input power spectra (DRIPS), similar to the input energy spectrum and shock response spectrum, give the power delivered to single-degree-of-freedom systems as a function of natural frequency. It is shown that the DRIPS is simply a smoothed version of the power spectrum of the input acceleration excitation. The DRIPS gives rise to a useful power-based data smoothing operation.

Keywords: Power, energy, random vibration

DOI: 10.3233/SAV-2009-0465

Journal: Shock and Vibration, vol. 16, no. 3, pp. 261-271, 2009