AsianScientist (Sep. 20, 2018) – A research group at Toyohashi University of Technology, Japan, has found a way to increase the sensitivity of ultrasonic wave-based detection methods for defects in materials. Their work is published in the Journal of the Acoustical Society of America.
The identifying defects in materials without damaging them is known as nondestructive testing. This is especially important in measuring the fatigue of materials—minute amounts of damage which accumulate and eventually cause the material to break.
One method to perform fatigue testing is to use ultrasonic waves. However, the current sensitivity of this method is low, which means that defects are only detected when a relatively large amount of damage to the material has occurred. Hence, there is a need to improve the lower detection limit of ultrasonic wave detection technology.
In the present study, researchers led by Assistant Professor Yosuke Ishii of Toyohashi University of Technology identified a ‘three-wave interaction’ in which two intersecting ultrasonic waves produce a third small ultrasonic wave within a material plate. This third wave exhibits varying intensity in response to material damage and can therefore be used for nondestructively testing thin plate structures.
The research team noted that their technology could make it possible to accurately evaluate material damage that is too small to be detected with existing technology, thereby improving the safety and reliability of socially important structures such as power generation plants and airplanes.
The article can be found at: Ishii et al. (2018) Finite-element Analysis of Non-collinear Mixing of Two Lowest-order Antisymmetric Rayleigh-lamb Waves.
Source: Toyohashi University of Technology; Photo: Shutterstock.
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