Fiber Bragg Grating-Based System for 2-D Analysis of Vibrational Modes of a Steel Propeller Blade
Journal of Lightwave Technology
Fiber bragg grating-based system for 2-D analysis of vibrational modes of a steel propeller This is the published version of the paper. This version of the publication may differ from the final published version. Permanent repository link: http://openaccess.city.ac.uk/4982/ Link to published version: http://dx. Abstract-This paper reports results obtained using Fibre Bragg Grating (FBG)-based sensors to investigate the displacement mode shapes of a cantilevered steel propeller blade, using FBG
... r blade, using FBG arrays for vibration monitoring for the first time. The experimental data obtained are cross-compared with those from a finite element analysis of the same blade, undertaken using proprietary software. In the experimental configuration used, a network of gratings, forming a series of sensor arrays, was mounted on the blade under study to monitor its bending modes, whilst a further set was mounted perpendicular to this array to monitor torsional modes. To obtain the shape of the strain modes generated in the blade at specific frequencies, the dynamic response of the FBG arrays, as a function of time, was captured and then processed using Fourier Transform algorithms to show the natural frequencies of the blade. As a result, the displacement modes shapes for the bending, torsional and coupled modes of the first nine natural frequencies of the plate were obtained. The experimental data show very good agreement with theoretical analysis. This work demonstrates the potential of using the lightweight, minimally invasive sensing technique described for the analysis of propeller blades and thus illustrating an effective method to overcome the deleterious effects of propellers seen in some commercial propeller designs.