Structural health monitoring using scanning laser vibrometry: II. Lamb waves for damage detection

Guided acousto-ultrasonic waves have great potential for structural health monitoring applications. Lamb waves are the most widely used guided waves for damage detection in metallic and composite structures. These waves, once introduced to a structure, can propagate long distances. Nevertheless the method still requires a significant number of transducers for monitoring large structures. Recent years have shown various applications of non-contact generation and sensing of Lamb waves. This paper proposes a new scanning technique based on laser vibrometry. The method is applied for damage detection in simple aluminium plates and validated using numerical simulations. The study shows the potential of the method for simple and rapid detection, location and monitoring of damage in structures.