Bioinspired low-frequency material characterisation
Hopper, C.; Assous, S.; Wilkinson, P.B.; Gunn, D.A.; Jackson, P.D.; Rees, J.G.; O'Leary, R.L.; Lovell, M.A.. 2012 Bioinspired low-frequency material characterisation. Advances in Acoustics and Vibration, 2012, 927903. 10.1155/2012/927903Before downloading, please read NORA policies.
New-coded signals, transmitted by high-sensitivity broadband transducers in the 40–200 kHz range, allow subwavelength material discrimination and thickness determination of polypropylene, polyvinylchloride, and brass samples. Frequency domain spectra enable simultaneous measurement of material properties including longitudinal sound velocity and the attenuation constant as well as thickness measurements. Laboratory test measurements agree well with model results, with sound velocity prediction errors of less than 1%, and thickness discrimination of at least wavelength/15. The resolution of these measurements has only been matched in the past through methods that utilise higher frequencies. The ability to obtain the same resolution using low frequencies has many advantages, particularly when dealing with highly attenuating materials. This approach differs significantly from past biomimetic approaches where actual or simulated animal signals have been used and consequently has the potential for application in a range of fields where both improved penetration and high resolution are required, such as nondestructive testing and evaluation, geophysics, and medical physics.
|Programmes:||BGS Programmes 2010 > Geoscience Technologies|
|Date made live:||22 Jun 2012 11:26|
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