Fiber Bragg Grating-Based System for 2-D Analysis of Vibrational Modes of a Steel Propeller Blade

Abstract

(2014). Fiber bragg grating-based system for 2-D analysis of vibrational modes of a steel propeller blade. Journal of Lightwave Technology, 32(23), pp. 3991-3997. doi: 10.1109/JLT.2014 This is the accepted version of the paper.This version of the publication may differ from the final published version. 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 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. Permanent

In-Fiber Bragg Grating Impact Force Transducer for Studying Head–Helmet Mechanical Interaction in Head Impact

“…The key attributes of FBGs that make them an enabling transducer for the above measurements are immunity to electro-magnetic interference, resistance to corrosive and humid environments, and in some cases the small size of FBGs (125 micron diameter and sensing gage lengths typically 1 mm to 10 mm) is attractive when compared to relatively larger transducers. The ability to serial-multiplex and apply them to distributed measurements has made FBGs an enabling technology for structural health monitoring [9] applications. In recent years, with advances in swept-laser light sources, high-bandwidth photo-detectors, and oscillating interferometric cavities, FBGs can be interrogated at rates from DC to kHz and are therefore suited to both static and dynamic measurements.…”

A suite of optical fibre sensors for structural condition monitoring

“…Fibre Bragg Gratings (FBGs) have been explored widely for various structural condition monitoring [1] [2]. This is due to their key characteristics of producing wavelength encoded signals that are not susceptible to instrumentation drift or environmental variations.…”