“Off-the-Shelf” optical sensing fiber for easy integration with composite

Optical sensing techniques are increasingly being used by industrial designers and manufactures to prove products prior to entering production, or for long-term structural health monitoring over the life of the product. This technology makes it possible to monitor over large or intricate composites at multiple sensing points (2000+) on a single optical line.

The major benefit of optical fiber remains its size and its ability to replicate many traditional strain gauges without the complexity, weight or cost normally associated with electrical sensors. Manufacturers of aircraft wings or wind turbine blades for example are already familiar with this technique for identifying and pinpointing faults within materials. However, as the typical optical fiber is not much bigger than a human hair, this has also introduced some handling difficulties during the storage, preparation and application of the fiber during layup processes.

To resolve these difficulties, FBGS has introduced a new strain sensing fiber with a protective GFRP jacket (Glass Fiber Reinforced Plastic) material, making integration with the composite material easier for the technician. Supplied on a convenient spool, it is available in either a tape (SMT-01) or wire (SMW-01) format to suit the application be it a surface application, embedded or for monitoring civil / geo-technical structures outdoors. With dimensions of only 0,35mm and 1mm, they remain small enough to effectively transfer strain yet offer ease of handling as well as significant mechanical protection for applications in harsh environments.

Whilst fiber length, number of sensors and connector type can be specified by the customer, a new fiber is now available for trials and evaluation comprising 5 sensors over a 6,2m length of the coated fiber. It is now possible for companies in the aerospace, yachting, civil and wind industries to introduce this measuring technique, without the issues sometimes associated with the introduction of new technologies. And if already familiar with the application of traditional electric strain gauges, then this process should be comparatively straight forward.