Modal testing using impact excitation and a scanning LDV

Anthony B. Stanbridge; A. Z. Khan; David J. Ewins

doi:10.1117/12.307718

1 June 1998 Modal testing using impact excitation and a scanning LDV

Anthony B. Stanbridge, A. Z. Khan, David J. Ewins

Proceedings Volume 3411, Third International Conference on Vibration Measurements by Laser Techniques: Advances and Applications; (1998) https://doi.org/10.1117/12.307718
Event: Third International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, 1998, Ancona, Italy

Abstract

If a laser doppler vibrometer is used in a continuously- scanning mode, its output spectrum contains side-bands from which the response mode shape, as defined along the scan line, may be obtained. With impact excitation, the response is the summation of a set of exponentially-decaying sinusoids which, in the frequency domain, has peaks at the natural frequencies and at 'sideband' pseudo-natural frequencies, spaced at multiples of the scan frequency. Techniques are described for deriving natural mode shapes from these, using standard modal analysis procedures. Some limitations as to the types of mode which can be analyzed are described. The process is simple and speedy, even when compared with a normal point-by-point impact test survey. Information may also be derived, using a circular scan, on the direction of vibration, and angular vibration, at individual points.

Citation Download Citation

Anthony B. Stanbridge, A. Z. Khan, and David J. Ewins "Modal testing using impact excitation and a scanning LDV", Proc. SPIE 3411, Third International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, (1 June 1998); https://doi.org/10.1117/12.307718

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available