At the Saxony Textile Research Institute (STFI) in Chemnitz, sensor textiles for monitoring tasks have been developed in collaboration with partners in the industry. They are designed to check for functionality, reliability and safety in building applications, as well as the quality of maintenance work in the fields of wood and concrete construction. The systems can be used to measure stresses caused by moisture and/or bending/flexing.

Restoration work on load-bearing structures requires reliable measurement and monitoring systems. The degree of flex can be used as a measurement in the investigation of critical stress situations. Fibre-optic sensors incorporating a fibre-Bragg grating are ideal as they can measure changes in length precisely, with results that are reproducible and stable over the long term. The problem of attaching these optical sensors to the surfaces of building components has been solved using embroidery technology (the soutache embroidery process) to fix the optical fibres onto lamellar woven or knitted carbon or glass fabrics. The fibre-optic sensor can be positioned freely on the surface as required, and practicable solutions for connecting the measurement technology are available. Long-term tests have demonstrated the functionality of the system as a whole. The carbon fibre structures with integral sensors are attached to the relevant load-bearing element using a wet lamination process. The measurements are collected by means of a spectrometer.

Signal quality tests have confirmed the finish of the optical fibres to be free of damage.

In a pilot project, the sensor textiles were used successfully to monitor snow loads on light hall structures. The completed monitoring system, SENSuTEX, which can be obtained from project partner GGB, is available for monitoring tasks in the fields of civil engineering and high-rise buildings.

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[Gisela Gozdzik]