Share Email Print

Proceedings Paper

Temperature-compensated strain measurement using FBG sensors embedded in composite laminates
Author(s): Nobuhira Tanaka; Yoji Okabe; Nobuo Takeda
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

For accurate strain measurement by fiber Bragg grating (FBG) sensors, it is necessary to compensate the influence of temperature change. In this study two devices using FBG sensors have been developed for temperature-compensated strain measurement. They are named hybrid sensor and laminate sensor, respectively. The former consists of two different materials connected in series: carbon fiber reinforced plastic (CFRP) and glass fiber reinforced plastic (GFRP). Each material contains an FBG sensor with a different Bragg wavelength, and both ends of the device are glue to a structure. Using the difference of their Young's moduli and coefficients of thermal expansion (CTEs), both strain and temperature can be measured. The latter sensor is a laminate of two 90 degree(s) plies of CFRP and an epoxy plate, and an FBG sensor is embedded in the epoxy plate. When the temperature changes, the cross section of the optical fiber is deformed by the thermal residual stress. The deformation of the fiber causes the birefringence and widens the reflection spectrum. Since the temperature can be calculated from the spectrum width, which changes in proportion to the temperature, the accuracy of the strain measurement is improved. The usefulness of these sensors were experimentally confirmed.

Paper Details

Date Published: 27 June 2002
PDF: 10 pages
Proc. SPIE 4694, Smart Structures and Materials 2002: Smart Sensor Technology and Measurement Systems, (27 June 2002); doi: 10.1117/12.472634
Show Author Affiliations
Nobuhira Tanaka, Univ. of Tokyo (Japan)
Yoji Okabe, Univ. of Tokyo (Japan)
Nobuo Takeda, Univ. of Tokyo (Japan)

Published in SPIE Proceedings Vol. 4694:
Smart Structures and Materials 2002: Smart Sensor Technology and Measurement Systems
Daniele Inaudi; Eric Udd, Editor(s)

© SPIE. Terms of Use
Back to Top