Structural Health Monitoring (SHM) refers to long-term monitoring of the structural integrity of static structures such as buildings, industrial plants, and civil infrastructure (dams, bridges, etc). Commonly measured parameters include:
- Stress and strain
- Physical geometry (changes in distance or angle)
- Composition (evidence for corrosion etc.)
Measurements are typically characterised by small, incremental changes over long periods of time (5-20 years or more), and monitoring points may be widely dispersed and difficult to access for servicing in the field. Monitoring systems for SHM must reflect this.
The monitoring system must be robust and reliable, and be able to maintain measurement stability over long periods of time, and/or be easily re-calibrated to an absolute reference. Sensors need to be cost effective to install, able to transmit information over long distances, and be resistant to long-term damage or degradation in the environment. ICON Technologies can supply monitoring systems optimised for SHM tasks.
Fibre Optic Measurement and SHM
Fibre optic measurement systems are ideally suited to SHM applications. In particular, fibre optic sensors:
- Are cost effective to install in large numbers over a distributed area.
- Can transmit over 10s of kilometers with negligible loss of signal.
- Are relatively straightforward to embed in structural elements.
- Are immune to electrical damage from lightening strike.
- Make absolute measurements that are not subject to drift over time.
- Have no electro-mechanical parts, so they are highly resistant to environmental damage or degradation.
ICON technologies can provide an SHM system based solely on fibre optic measurement, or combine fibre optics with other technologies that have been successfully applied to SHM, such as vibrating wire sensors, laser rangefinders, and cameras.