On the usability of phase-based video motion magnification for defect detection in vibrating panels

Phase-based Motion Magnification (PMM) has recently emerged as a potentially disruptive technology in the field of Optical Methods for Vibration Engineering. In facts, PMM allows to post-process high-speed video recordings in order to magnify small motions happening in a prescribed bandwidth. This work discusses the possibility of using PMM as a non-destructive inspection tool for defect detection and identification in vibrating panels. In particular, our strategy relies on measuring the low-frequency eigen-shapes aberration resulting from small defects, which are usually very localized in space but appears even at lower frequencies, making the approach suitable only for any high-resolution full-field optical technique. A novel Phase-based defect detection processing pipeline is described, and this work presents the preliminary feasibility results of our research. Validations were carried out by means of numerical simulations relying upon a photorealistic dynamic finite element model of a rectangular plate.