Damage detection in thick plate structures based on ultrasonic SH wave

Thick plate structures are widely used in large deep-sea scientific detection equipment, such as deep-sea human-occupied vehicles, but they are prone to local damage caused by fatigue due to the complex working environment load. To prevent structural failure due to damage accumulation, it is necessary to carry out structural health monitoring for thick plate structures. In this work, two half-ring thickness poled d₁₅mode omnidirectional shear horizontal (SH) wave piezoelectric transducers are used to form an exciter/receiver network, and the SH₂mode wave packet is selected as the damage location wave packet. Then, the reconstruction algorithm for the probabilistic inspection of damage and an algorithm based on the time of guided wave flight are applied for damage detection in a 30 mm-thick aluminium plate. Experimental results show that structural damage detection based on SH waves can effectively identify and locate thick plate structural damage and evaluate the damage depth.