Matrix laser vibrometer for transient modal imaging and rapid nondestructive testing

James M. Kilpatrick; Vladimir Markov

doi:10.1117/12.802929

Translator Disclaimer

17 June 2008 Matrix laser vibrometer for transient modal imaging and rapid nondestructive testing

James M. Kilpatrick, Vladimir Markov

Author Affiliations +

Proceedings Volume 7098, Eighth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications; 709809 (2008) https://doi.org/10.1117/12.802929
Event: Eighth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, 2008, Ancona, Italy

Abstract

This article describes the development and application of a 16x16 array (matrix) laser vibrometer based on a parallel architecture which supports fast 2D measurement of arbitrary (steady state, non-steady state, transient) solid body vibrations without beam scanning. The small size and low weight of the measurement probe, which is linked to a remote detector/processor unit via a flexible armoured fibre-optic umbilical, enables deployment in areas with restricted access. Incorporating aspects of high-speed electronic speckle pattern interferometry (ESPI) and laser Doppler vibrometry (LDV), the design is based on a hybrid fiber-optic/bulk optic interferometer which operates at a wavelength of 1550 nm. Test data illustrate high-speed capture of transient vibrations, showing the full 2D temporal evolution of surface deformation, including multiple resonant modes, of a center-pinned metal plate excited by a 1-50 kHz frequency chirp of 109 ms duration. We discuss preliminary data showing detection of sub-surface defects in composite materials, based on non-contact (frequency chirped) acoustic resonance of the locally damaged structure. For large area NDT the probe can be mounted on a lightweight XY gantry for automated multi-frame measurements.

Citation Download Citation

James M. Kilpatrick and Vladimir Markov "Matrix laser vibrometer for transient modal imaging and rapid nondestructive testing", Proc. SPIE 7098, Eighth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, 709809 (17 June 2008); https://doi.org/10.1117/12.802929

ACCESS THE FULL ARTICLE