Distributed strain sensing for structural monitoring applications

Strain sensors are a valuable tool for assessing the health of structures. The University of New Brunswick, in conjunction with ISIS Canada, is develo ping a distributed fibre optic strain sensor based on Brillouin scattering. This sensor can provide a virtually unlimited number of measurement points using a single optical fibre. A description of the operating principles of the system is given, along with a summary of laboratory test results. Stra in measurement accuracy as high as approximately +/- 11 mu epsilon has been demonstrated at 1 m spatial resolution. Spatial resolutions as short as 10 0 mm can be used, although with decreased strain measurement accuracy. Futu re development of the technology will include an enhancement allowing both strain and temperature to be measured simultaneously.