Acoustic sensor array for determination of undersea acoustic signatures

Author(s):  
Tom Chu ◽  
Jafar Saniie ◽  
Erdal Oruklu
2011 ◽  
Vol 324 ◽  
pp. 93-96 ◽  
Author(s):  
Amel Gacem ◽  
A. Doghmane ◽  
Z. Hadjoub

The determination of the characteristics and properties of thin films deposited on substrates is necessary in any device application in various fields. Adequate mechanical properties are highly required for the majority of surface waves and semiconductor devices. In this context, modelling the ultrasonic-material interaction, we present results of simulation curves of acoustic signatures for multiple thin film/substrate combinations. The results obtained on several structures (Al, SiO2, ZnO, Cu, AlN, SiC and Cr)/(Al2O3, Si, Cu or Quartz) showed a velocity dispersion of the Rayleigh wave as a function of layer thickness. The development of a theoretical calculation model based on the acoustic behaviour of these structures has enabled us to quantify the dispersive evolution (positive and negative) density. Thus, we have established a universal relationship describing the density-thickness variation. In addition, networks of dispersion curves, representing the evolution of elasticity modulus (Young and shear), were determined. These charts can be used to extract the influence of thickness of layers on the variation of elastic constants


2019 ◽  
Vol 53 (4) ◽  
pp. 627-645
Author(s):  
Claudia Valentina Popa ◽  
Alina Vasilescu ◽  
Simona Carmen Litescu ◽  
Camelia Albu ◽  
Andrei Florin Danet

2011 ◽  
Vol 324 ◽  
pp. 493-496
Author(s):  
Samia Bouhedja ◽  
F. Hamdi

In this work, we study the microstructure of porous alumina Al2O3 through the acoustic signature behavior V(z). This function depends on the low porosity when annular lenses conditions at an operating frequency of 1 GHz are used. In non destructive control, this quantitative investigation which allows the determination of mechanical materials properties is of a great importance in the measurement of the surface waves attenuation in this type of biomaterials. Hence, we have numerically simulated the porous alumina acoustic signatures through variable occultation of generating rays at the lens center, in order to quantify the occultation limiting angle. Consequently, the evaluation of the equivalent Rayleigh velocity using the fast Fourier transform (F.F.T) spectra was achieved thanks to the suppression of the Rayleigh mode generation.


2010 ◽  
Vol 127 (3) ◽  
pp. 1780-1780
Author(s):  
Vladimir E. Ostashev ◽  
Christian G. Reiff ◽  
Michael V. Scanlon ◽  
Sandra L. Collier ◽  
D. Keith Wilson

2008 ◽  
Vol 124 (4) ◽  
pp. 2509-2509
Author(s):  
Vladimir E. Ostashev ◽  
Michael V. Scanlon ◽  
Christian Reiff ◽  
D. Keith Wilson ◽  
Sergey N. Vecherin
Keyword(s):  

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