Linear and nonlinear damage detection using a scanning laser vibrometer

Article type: Research Article

Authors: Vanlanduit, Steve | Guillaume, Patrick | Schoukens, Johan | Parloo, Eli

Affiliations: Department of Mechanical Engineering (WERK), Brussel, Belgium | Department of Electrical Engineering (ELEC), Brussel, Belgium

Note: [] Corresponding author: S. Vanlanduit, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium. Tel.: +32 2 629 28 05; Fax: +32 2 629 28 65; E-mail: steve.vanlanduit@vub.ac.be

Abstract: Because a Scanning Laser Vibrometer (SLV) can perform vibration measurements with a high spatial resolution, it is an ideal instrument to accurately locate damage in a structure. Unfortunately, the use of linear damage detection features, as for instance FRFs or modal parameters, does not always lead to a successful identification of the damage location. Measurement noise and nonlinear distortions can make the damage detection procedure difficult. In this article, a combined linear-nonlinear strategy to detect and locate damage in a structure with the aid of a SLV, will be proposed. To minimize the effect of noise, the modal parameters will be estimated using a Maximum Likelihood Estimator (MLE). Both noise and nonlinear distortion levels are extracted using the residuals of a two-dimensional spline fit. The validation of the technique will be performed on SLV measurements of a delaminated composite plate.

Journal: Shock and Vibration, vol. 9, no. 1-2, pp. 43-56, 2002