Mode Filtering of Continuous Scanning Laser Doppler Vibration Data

The paper illustrates the idea of using theoretical knowledge of specific structure's mode shapes as a way of filtering time domain data obtained by Continuous Scanning Laser Doppler Vibrometry (CSLDV). The CSLDV output measures the structure vibration joining together the spatial and time information. It is proposed here to exploit the a priori knowledge of the candidate mode shape spatial distributions to extract from the vibration data the resonance frequency information with high accuracy. That technique is based on the concept that modal analysis ends up with a final abstraction and labelling of the mode shapes on the basis of their nodal lines position, i.e. first, second bending and/or torsional, etc. The expected mode is compared with the experimental data in order to evidence the information on the frequency at which that mode occurs.