Identification of vibration excitation using a regularized Finite Element operator and a deconvolution post-process
Résumé
The Force Analysis Technique FAT is an experimental inverse approach that aims to identify vibration sources from the measurement of displacement field of a structure. Based on the verification of the local dynamic behaviour of the structure, the FAT constitutes an interesting inverse problem since boundary conditions and sources outside the studied domain may not be known. In its first developments, the FAT was written for analytically known structures like beams, plates and shells but more recently, its adaptation to more complex structures was possible thanks to the use of Finite Element Method and model reductions. In this mathematical adaptation, the regularization of the problem is done by a double inversion of the numerical operator where the well known Tikhonov regularization is applied in the second inversion. In order to correct the smoothing effect on regularized results, it is then proposed to apply a deconvolution post-process made by the Richardson-Lucy algorithm. After the description of all steps constituting the method, several experimental results on structures excited by a point force are shown. In addition to the location of the force, it is also shown how the quantification of the force is improved by the deconvolution in comparison with direct measurements.
Domaines
Acoustique [physics.class-ph]
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