Calculation of Guided Wave Dispersion Characteristics Using a Three-Transducer Measurement System

Applied Sciences

Bhavin Engineer¹  Borja Hernandez Crespo²  CharlesR. P. Courtney² 

[1] Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL, UK;Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, UK;

关键词: guided waves;    lamb wave;    dispersion curves;    phase velocity;    group velocity;    signal processing;   

DOI  :  10.3390/app8081253

来源: DOAJ

【 摘 要 】

Guided ultrasonic waves are of significant interest in the health monitoring of thin structures, and dispersion curves are important tools in the deployment of any guided wave application. Most methods of determining dispersion curves require accurate knowledge of the material properties and thickness of the structure to be inspected, or extensive experimental tests. This paper presents an experimental technique that allows rapid generation of dispersion curves for guided wave applications when knowledge of the material properties and thickness of the structure to be inspected are unknown. The technique uses a single source and measurements at two points, making it experimentally simple. A formulation is presented that allows calculation of phase and group velocities if the wavepacket propagation time and relative phase shift can be measured. The methodology for determining the wavepacket propagation time and relative phase shift from the acquired signals is described. The technique is validated using synthesized signals, finite element model-generated signals and experimental signals from a 3 mm-thick aluminium plate. Accuracies to within 1% are achieved in the experimental measurements.

【 授权许可】

Unknown