Critical conditions of a structure are highly related to localised effects such as onset and progressive crack formation.
The continuous fibre optic strain measurement used by Sensical is ideal for an early detection and precise observation of such symptoms. Sensor fibres running along the surface or embedded in the structure measure strain of up to 1mm resolution. The length of sensor can reach up to 50m, even 400m by linking several sensor strands together.
The measured strain signal is highly sensitive to any form of discontinuity, be it cracks in concrete or steel, voids, inclusions or breaks.
Due to the high temporal resolution of up to 100 measurements per second, activities such as crack growth or the structure’s response to changes in load can be precisely registered early on.
Sensor configurations designed for specific measuring tasks consider the respective measurand requirements (strain and / or temperature) as well as accuracy, robustness and durability.
The basis for this type of measurement is the reflection of light waves, coupled into glass fibres, off inevitable and non-critical impurities in the fibre.
The scattered light can be likened to having the properties of a fingerprint unique to each individual fibre. This fingerprint is invariant throughout the fibre’s operating time and provides a frame of reference for every measurement carried out. Hence interruptions in measurement pose no problem. Any fibre reattached to the measuring instrument is identified by its unique fingerprint and can resume a measurement, even years later.
Using strain as the basic measurand further, derived, measurands can be determined.
Accordingly, an appropriate sensor design allows for the temperature to be determined directly by considering the physical properties of the glass material (thermal expansion coefficient). Further measurands such as deflection or mechanical stress as well as vibrations can be calculated following the measurements.
The afore mentioned properties make continuous fibre optic strain measurement the ideal instrument for monitoring built infrastructure.
For the timely detection of critical conditions as well as for the detection and observation of load bearing reserves and the prediction of the structure’s lifespan.
Are you interested in scientific sources to do with this technology?
Our list for publications and links may help.
- Künzel, A. (2016),Parameteridentifikation auf Basis faseroptisch gemessener quasi-kontinuierlicher Dehnungssignale, Dissertation;
- Künzel, A., Petryna, Y. (2016),Parameter identification based on quasi-continuous strain data captured by high resolution fiber optic sensing.
In: 8thEuropean Workshop On Structural Health Monitoring (EWSHM 2016), 05.-08.07.2016, Bilbao, Spanien;
- Vogdt, F.D. (2017),Erprobung experimentell basierter Evolutionsgleichungen für ein Werkstoffgesetz von Beton, Dissertation;
- Speck, K. , Vogdt, F. , Curbach, M. and Petryna, Y.(2019), Faseroptische Sensoren zur kontinuierlichen Dehnungsmessung im Beton. Beton‐ und Stahlbetonbau, 114: 160-167. doi:10.1002/best.201800105