ESTIMATION OF MODAL PARAMETERS OF A BEAM UNDER RANDOM EXCITATION USING A NOVEL 3D CONTINUOUSLY SCANNING LASER DOPPLER VIBROMETER SYSTEM AND AN EXTENDED DEMODULATION METHOD
Loading...
Links to Files
Permanent Link
Author/Creator
Author/Creator ORCID
Date
2021-01-01
Type of Work
Department
Mechanical Engineering
Program
Engineering, Mechanical
Citation of Original Publication
Rights
This item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please see http://aok.lib.umbc.edu/specoll/repro.php or contact Special Collections at speccoll(at)umbc.edu
Distribution Rights granted to UMBC by the author.
Access limited to the UMBC community. Item may possibly be obtained via Interlibrary Loan thorugh a local library, pending author/copyright holder's permission.
Distribution Rights granted to UMBC by the author.
Access limited to the UMBC community. Item may possibly be obtained via Interlibrary Loan thorugh a local library, pending author/copyright holder's permission.
Subjects
Abstract
A novel three-dimensional (3D) continuously scanning laser Doppler vibrometer (CSLDV) system that contains three CSLDVs and an external controller is developed to measure 3D vibration of a structure under random excitation, and a new operational modal analysis method is proposed to estimate its 3D modal parameters, by extending the conventional demodulation method. Calibration among three CSLDVs in the 3D CSLDV system is conducted to ensure that three laser spots can continuously and synchronously move along the same scan path on the structure. The extended demodulation method can estimate undamped mode shapes of the structure under random excitation by filtering raw response with a bandpass filter and demodulating the filtered response. Experimental investigation on one-dimensional (1D) and 3D CSLDV measurements for modal parameter estimation is conducted on a beam under white-noise excitation to validate the extended demodulation method and examine the accuracy of the 3D CSLDV system.