Use of FBG sensors in SHM of aerospace structures

Jayantha Epaarachchi,Gayan C. Kahandawa,Hao Wang

doi:10.1117/12.916111

Abstract

This paper discusses the use of Fibre Bragg grating sensors (FBG) in structural health monitoring (SHM) of Fibre reinforced polymer (FRP) aerospace structures. The diminutive sensor provided the capability of embedding inside FRP structures in order to monitor vital potential locations for damage. Some practical problems associate with manufacturing process of FRP with embedded FBG sensors, interrelation of distortion to FBG spectra with damage, and interpretation of FBG spectral responses for identifying the damage will be discussed.

Highlights

Fiber reinforced polymer (FRP) composites have been used as an engineering material for more than six decades
This paper details some significant findings on the use of the fiber Bragg grating (FBG) sensors for structural health monitoring (SHM) in aerospace fiber reinforced polymer (FRP) structures
Since the research and development (R&D) in the aircraft industry and space exploration agencies have been focused on the FRP for many years, most of the advanced fiber composites available today one way or another have their origins in these fields

Summary

1.Introduction

Fiber reinforced polymer (FRP) composites have been used as an engineering material for more than six decades. Since the research and development (R&D) in the aircraft industry and space exploration agencies have been focused on the FRP for many years, most of the advanced fiber composites available today one way or another have their origins in these fields. The main disadvantages of using FRP composites in the aircraft industry are their difficulty for repair, anisotropic behavior, degradation of strength with time, high initial setup cost, and most importantly the complex failure. Because of these undesirable properties, the FRP composite structures in the aircraft need to be closely monitored to prevent unexpected failure. These structures can include stress-concentrated regions such as pin-loaded holes and other cutouts. In view of aforementioned issues, the structural health monitoring (SHM) technique has recently been developed for these composite structures [4, 5]

SHM for FRP aerospace structures

Use of FBG sensors for SHM in aerospace structures

Embedded FBG sensors

Embedding process

30 Distorted peak during curing

Loading effect of the FBG sensor

FBG interrogation

Self distortion of the FBG sensor

Reading FBG response and identification of damage

Processing FBG data

Fixed FBG filter decoding system

Conclusions