from the mood-rings-are-making-a-comeback dept.
Civil engineers at Vanderbilt University's Laboratory for Systems Integrity and Reliability (LASIR) are developing a nanoparticle coating which changes its luminosity depending on how much stress it is under. This has a bright potential in creating sensors to determine when sections of infrastructure need reinforcement or replacement.
"Currently, there are two ways to keep everything from bridges to aircraft safe," said LASIR Director, Douglas Adams, Daniel F. Flowers Professor of the civil and environmental engineering. "One is to send people out to look at them with a flashlight. The problem with this is that it is labor-intensive and the people can't see very small cracks when they form. The other is to install elaborate sensor networks that constantly look for small cracks and detect them before they grow too large. The problem is that these networks are very expensive and, in the case of aircraft, add a lot of weight. "So we need to somehow change the materials we are using so they illuminate these tiny cracks."
The team's initial studies, published last April in the Proceedings of the SPIE Conference on Sensors and Smart Structures Technologies for Civil, Mechanical and Aerospace Systems, have determined that adding a tiny concentration of special nanoparticles (1 to 5 percent by weight) to an optically clear polymer matrix produces a distinctive light signature that changes as the material is subjected to a broad range of compressive and tensile loads.
[...] In this fashion, the researchers have verified that the material can act as a new kind of strain gauge that permanently records the cumulative amount of stress that the material to which it is applied experiences.
(Score: 2) by VLM on Monday November 28 2016, @03:04PM
You still need to program and build a robot to do the labor of looking at all that stuff, even if its easy to identify.
In my infinite spare time I was thinking about using computer vision to do magna-flux Q+A. Its an interesting machine vision problem and non-trivial robotic problem. Of course its probably already been done and is already shipping.
(Score: 0) by Anonymous Coward on Monday November 28 2016, @04:45PM
(Score: 2, Informative) by Anonymous Coward on Monday November 28 2016, @09:26PM
Stress Coat used with polarized light has been around for a long time. Google found a fairly recent patent in the general area,
https://www.google.com/patents/US6219139 [google.com]
Before that, brittle lacquer was commonly used and there is still at least one supplier for similar coating,
http://www.stresskote.com/ [stresskote.com]
Both of these visual/test techniques are going out of style as Finite Element (computational) stress analysis for single-cycle loading cases is getting easier and faster.
What is special about this new product is that it claims to respond to cumulative stress--many load cycles that leads to fatigue failures. While there are people that claim to do computational fatigue prediction, I believe this is still a work in progress.
(Score: 2) by jmoschner on Tuesday November 29 2016, @10:51AM
Curious to know how dirt, exhaust fumes, and other environmental factors will impact the coating or if they will interfere with reading the results. Also curious how this plays with the paint or other coatings that are put on structures to help prevent corrosion.