Structural health monitoring using scanning laser vibrometry: I. Lamb wave sensing

Structural health monitoring using Lamb waves is based on guided waves introduced to a structure at one point and sensed at a different location. Actuation and sensing can be accomplished using various types of transducer. The paper demonstrates a non-contact method for low-frequency Lamb wave sensing. The technique utilizes a laser Doppler velocimeter. Lamb wave responses are enhanced using data smoothing and filtering procedures. The results are validated using classical piezoceramic-based sensing and numerical simulations. The study shows the potential of laser vibrometry for Lamb wave sensing.