An Optical Fibre Sensor for Acoustic Wave Mode Decomposition

摘要

This paper reports on the development of an optical fibre sensor comprising an array of uniformly distributed Bragg gratings that are configured to allow for the detection and modal decomposition of structural plate waves. Aspects of the design, fabrication and validation of the sensor are discussed. Laser vibrometry (LV) and advanced numerical modeling are used to demonstrate the fidelity of dynamic strain measurements furnished by a fibre Bragg grating. The sensor is applied in an experimental study involving a metal plate where it is shown that mode conversion of Lamb waves caused by a structural inhomogeneity is robustly measured.