Selected Applications of Fiber-Optic Sensors Based on Highly Birefringent Fibers in Engineering Mechanics
The need for fiber-optic sensor (FOS) technology in the broad area of engineering mechanics is now well documented. Civil engineering structures such as highway and railway bridges, dams, tunnels, large buildings and underground mines must resist environmental and in-service loads due to winds, earthquakes, traffic, thermal effects, construction or environmental damage. For safety and maintenance purposes their response must be carefully monitored. This information is needed to assess their overall “health” and to increase engineering knowledge for future projects. Pressure and strain gauges, accelerometers and tiltmeters are among the variety of electrical and non-electrical transducers which can be directly embedded in concrete, earth, rock, borehole or tunnel lining to sense and monitor structural loads and responses. None are well suited to more demanding civil engineering environments. Non-electrical hydraulic devices are costly in terms of labour-intensive inspection, maintenance and repairs; they are difficult to multiplex and impossible to use for dynamic measurements. Electrical measuring devices are out of the question in open-air structures (risk of lightning), and in mining environments (risk of explosion). For these applications fiber-optic sensors offer significant metrological improvement: electrical passivity, high bandwidth, safety in corrosive or explosive environments, immunity to EMI, high sensitivity, miniature dimensions, possibility of remote operation and direct compatibility with increasingly present fiber-optic data transmission networks.
KeywordsPressure Sensor Pressure Cell Tunnel Lining Polarization Mode Dispersion Highly Birefringent
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- 1.E. Udd, Editor, “Fiber Optic Sensors”, John Wiley & Sons, New York, 1991.Google Scholar
- 13.W. J. Bock, A. W. Domanski, US Patent 4 920 261 (1990), Canadian Patent 1 322 109 (1993).Google Scholar
- 14.W. J. Bock, W. Urbanczyk, M. Beaulieu, J. Wojcik “White-light interferometric fiber-optic pressure sensor”, Proc. IEEE Instr.Meas.Tech.Conf., Hamamatsu, Japan, May 10–12, 406–11, (1994).Google Scholar