Strain Monitoring in Stiffened Composite Panels Using Embedded Fibre Optical and Strain Gauge Sensors

Abstract : This paper describes an implemented structural health monitoring (SHM) system based on Fibre Optic Bragg Grating (FOBG) sensors and standard resistance strain gauges (SGs) placed onto/into a stiffened carbon fibre-reinforced polymer (CFRP) fuselage panel. The role of the FOBG sensor system was to monitor the structural integrity of the reference, impacted and fatigued panels under compression loading. The FOBG and/or SG sensors were placed (embedded or bonded) at various locations into and/or onto the structure. The functionality of the SHM system was verified by experimental evaluation. The comparability and reliability of the results gained from the FOBG sensors and resistance strain gauges is discussed. This paper presents the key objectives from a European Union funded collaborative Project, inside the Clean Sky Joint Technology Initiative (CS JTI), investigating the SHM systems for CFRP fuselage stiffened panels based on fibre optic Bragg grating sensors for the Green Regional Aircraft Integrated Technology Demonstrator (GRA ITD).