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Flexible ultrasound patch could assist railway track inspection

General Discussion
#1

26 March 2018

Flexible ultrasound patch could assist railway track inspectionBy Robert Scammell

Researchers at the University of California San Diego have developed a stretchable and flexible probe that could make it easier to perform ultrasound imaging on odd-shaped structures such as railway tracks.

The probe consists of a thin patch of silicone elastomer patterned with an ‘island-bridge’ structure; small electronic parts make up the islands and connecting spring-like structures form the bridges.

It is the flexibility of these bridges, made from spring-shaped copper wires, that allows the patch to bend to irregular surfaces, while the islands contain electrodes and piezoelectric transducers which produce ultrasound waves when electricity passes through them.

In contrast, conventional ultrasound devices have a flat and rigid base which prevents them from maintaining good contact when scanning across curved, wavy or angled surfaces.

“Elbows, corners and other structural details happen to be the most critical areas in terms of failure—they are high-stress areas,” said professor of structural engineering at UC San Diego and co-author of the study Francesco Lanza di Scalea.

https://www.railway-technology.com/news/flexible-ultrasound-patch-assist-railway-track-inspection/

#2

Author’s name Scammell brings to mind an important bit of UK automotive history.

#3

Funny, it’s a neat idea to make a probe that is effectively a flexible, conformable sheet.

But clearly the team does not know how rails are checked… you can’t have a person applying a sheet every 2 feet and taking a measurement and lifting it. It would take years to do a few miles of track.

Modern ultrasound units scan the rail while in motion. It would take too long any other way.

Greg

#4

Perhaps the Patches are to further define the defect AFTER the rolling detector has located an area.

#5

I watched a lot of videos on this track inspection stuff, many of them were by the manufacturers of the equipment. They find anything and they cut out a nice chunk of rail, most of these are fractures and apparently replacing a 1 foot section is not much different from a 3 or 4 foot section.

But, clearly it could be used for a more in-depth inspection at the time or after removal.

My point is the information gleaned is after the fact of detection by other means. I just think it was a poor example, since I doubt that railroads spend much time analyzing these cracks that have been pretty well known for over 100 years.

I would think that a better example, like putting a patch sensor on a structural component of a car or plane that is being destructively tested, so you could “watch” the failure mode start and progress.

Greg

#6

Too bad it can’t be retro fitted on a bridge in Miami…

Seems like there should be a market that caused it’s birth…