Damage Detection of Multi-structures Based on Full-field Steady-state Ultrasonic Imaging Technique Using a Dual Laser Scanner

This paper presents a damage detection and visualization method using a dual laser scanning system. The wavenumber-based damage detection technique is applied to the measured structural responses for damage identification. Each piezoelectric transducer, which is attached to structures, provides different fixed frequency standing-waves. The steady-state response of two structures is simultaneously measured using the dual laser scanner system that involves a single point laser doppler vibrometer laser beam that is separated through a beam splitter. The measured steady state response of two structures are then processed and rearranged for damage detection of each structure using multi-structure steady-state response separation techniques. Several experiments were performed on aluminum and composite plates to validate the proposed techniques. The results demonstrated that the dual laser scanning system allowed damage detection and visualization of multi-structure with improved speed.