Carbon laminates with RE doped optical fibre sensors

Abstract

Abstract:A new type of luminescent optical fibre sensor for structural health monitoring of composite laminates (CFRP) is proposed. The Nd 3+ doped multi-core doubleclad fibre incorporated in composite structure was used as a distributed temperature sensor. The change of luminescence intensity (Nd 3+ ions) at the wavelength of 880 nm ( 4 F 3/2 → 4 I 9/2 ) and 1060 nm ( 4 F 3/2 → 4 I 11/2 ) was used for internal temperature monitoring. The special construction of optical fibre was used as it assures an efficient pumping mechanism and, at same time, it increases the measuring sensitivity. The linear response with relative sensitivity 0.015 K −1 was obtained for temperature range from 30 up to 75 ∘ C. The manufacturing process of CFRP with embedded optical fibre sensor is also discussed.

UV sensing optode for composite materials environment monitoring

“…The stability of mechanical properties of composite materials depends on the combinations of numerous environmental and service conditions. The most important are: maximum static load, vibrations (fatigue parameters), temperature, moisture, ultraviolet, chemically aggressive environment [11][12][13][14][15][16][17][18][19]. The monitoring of such parameters is critical especially for testing new materials.…”

“…Well known optical phenomena (optical radiation scattering, Bragg grating reflectivity, micro and macro-bend losses) can be used for mechanical behaviour monitoring [8,[25][26][27][28]. Additionally, luminescent optical fibres, embedded in the material structure, can be used for temperature monitoring [15]. Optical fibre con-structions offers some specific advantages over electrical sensors since they can operate in the wide temperatures range and high intensity of electromagnetic fields.…”