Researchers at the University of Strathclyde (
www.strath.ac.uk) have developed an ultrasound sensor to detect cracks in structures such as aircraft engines, oil and gas pipelines and nuclear plants.
A university spokesman said that this device — known as a transducer — identifies structural defects through varying ultrasonic frequencies and “overcomes the limits of other devices, which are based on rigid structures and have narrow ranges”. It is claimed to be the first device of its kind in the world.
Tony Mulholland of Strathclyde’s Department of Mathematics and Statistics said: “The transducer has a flexible structure, based on a natural phenomenon known in mathematics as fractals. These are irregular shapes that recur repeatedly to form objects such as snowflakes, ferns and cauliflowers, making their structure appear more complex than it actually is.
“Fractal shapes and sound-waves are characterised by having geometrical features on a range of length scales. However, man-made transducers tend to have a very regular geometry, similar to a chess-board, and that restricts our ability to use this technology to find cracks and flaws in structures where safety is critical.
“The reason transducers are still made this way is mainly historical; they were made by an engineer with a saw. Now, with 3-D printing, computer-based manufacturing and more laser technology, the transducer we have designed is increasingly viable.
“We know that, if we can send out sound-waves that are complicated and have different frequencies, we can work towards simulating what nature does. If there are defects in a nuclear plant or an oil pipeline, we would be able to detect cracks that have a range of sizes — and at an early stage in their development. This is something industry is telling us it needs, and we are responding to that need.”
Dr Mulholland was partnered in the study by Ebrahem Algehyne, a research student at Strathclyde’s Centre for Ultra-
sonic Engineering. The research has been published in the IMA Journal of Applied Mathematics.