Optimizing Structural Health Monitoring Using Optical Technology

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This webinar was held May 13, 2020

How can you ensure the safety and longevity of our infrastructure? The answer – by employing predictive and cost-effective infrastructure monitoring solutions that deliver reliable data on structural behaviour and status.

These solutions often consist of a combined usage of different technologies. HBM provides the entire measurement chain for these types of applications, from sensor to software, through the acquisition hardware.

In this webinar we will introduce you in how optical technology solutions are used to overcome challenges in structural health monitoring measurements. With the upcoming optical interrogator MXFS, optical technology is integrated into one of the most successful data acquisition platforms of HBM: the QuantumX. You’ll learn more about this powerful combination of the modular concept of QuantumX and its capabilities with the most wanted advantages of optical technology and how they benefit your measurement projects.

This webinar will discuss:

•   The common challenges of structural monitoring systems
•   How optical technology benefits such applications
•   The new optical interrogator from HBM, including its advantages, namely for infrastructure monitoring.

Speaker:

Cristina Barbosa

Product Manager
HBM Optical Business

Contact:

[email protected]

Download Webinar Materials

Optimizing Structural Health Monitoring Using Optical Technology (PDF)

Questions from Webinar Participants Answered by Cristina Barbosa

HBM FiberSensing supplies cables with several FBG strain and/or temperature sensors.

Yes, HBK currently offers off-the-shelf solutions based on FBG for measuring strain, temperature, displacement, tilt and acceleration.

Learn more

Yes, we have projects running in India for structural health monitoring using Fiber Bragg Grating technology.

Yes. We have teams within HBK who can support installation almost worldwide.

Sensors embedded in concrete do need special care during installation namely because:

Sensors have to be installed at a late stage of the construction work on the structure (as close as possible to the concreting operation), which means that they have to be installed while regular construction work is occurring the timing is usually critical and quite intense.
Sensors and cables are fragile items and workers must be aware of their existence and take this fragility into account.
Concrete pouring is a tough process, depending on the type of concrete and on the method used.

So, regarding the sensor location, care must be taken to prevent damage resulting from the whole process, for example:

Using a tight net to cover the sensor will ensure that large aggregates from the concrete mixture will not hit the sensor.
Using the vibrator at safe distances away from the sensor will ensure that the vibration process does not harm the sensors.
Embedding the sensor location in concrete in advance of the whole operation allows a controlled process over the sensor.

Care must also be taken with the cable paths, and we always suggest the use of tubes to protect the cables.

In addition, you must pay attention to where the cables exit from the concrete.

Again, several strategies can be used, and care is needed in all of them especially when removing the formwork to ensure that cables are not damaged by the process. A damaged cable close to its exit from the concrete is impossible to repair.

The QuantumX MXFS is compatible with FBG-based sensors from any supplier, as long as these are not based on special FBG’s (for example: phase-shifted FBG, long period FBG).

It measures peaks with different reflectivity, within the available dynamic range.

catman 5.4.1 is the first version of catman to support the QuantumX MXFS Interrogator.

Find out more

At the moment, QuantumX MXFS is compatible with catman AP but not with catman Enterprise. Please contact HBM if you have the need for this compatibility.

The QuantumX MXFS BraggMETER module has two acquisition rates that can be configured by the user: 100S/S and 2000S/S. On top of the set acquisition rate, different sampling rates can be defined on the device by down sampling.

The acquisition rate defines the sweeping speed of the laser as one complete sweep on the overall wavelength spectrum is needed for each sample.

The sampling rate corresponds to the number of samples that are made available which is also user definable.

No. The stated sampling rate is the same despite the number of sensors that are connected. All sensors can be acquired simultaneously and in parallel at the maximum acquisition rate.

The optical interrogators from HBK (DAQ) need to be connected to a PC for configuration and data saving. However, there are models, that can then be disconnected from the PC and operate as standalone and record data internally (FS22 Static).

Check for further details on our product page FS22 Industrial BraggMETER.

This is a tricky question to answer as it depends on the type of sensors and the structure being monitored. However, in our experience, for a system mainly consisting of strain and temperature measurements, and a structure that is regular and does not require special protection, or involve long distances, this number would be around 60 measuring points.

Optical sensors are available with different types of cables providing different levels of protection, and dependant on the environment, they might require further protection. For example, for cables embedded in concrete, it is advisable to use flexible tubes for the cable path; for cables deployed on a surface inside a bridge deck, a flexible tube, half a cane or a cable path tray could all be suitable solutions.