Article

Measurements of velocity and attenuation of leaky waves using an ultrasonic array.

Department of Physics, University of Windsor, 401 Sunset Avenue, Windsor, Ont., Canada N9B 3P4.
Ultrasonics (Impact Factor: 1.81). 03/2006; 44(2):182-7. DOI: 10.1016/j.ultras.2005.10.005
Source: PubMed

ABSTRACT A new method of measuring velocity and attenuation of leaky surface waves is presented. A single focused transmitting transducer and linear receiving array in a pitch-catch arrangement are used in the proposed system. The spatial distribution of the acoustic field in the leaky wave is recorded by the array, and the parameters of the leaky wave can be obtained by processing the output waveforms. In comparison with existing material characterization systems, the mechanical scanning of the transducers is not used any more, and the measurement time is only limited by the time of the wave propagation and speed of the electronic data acquisition system.

0 Followers
 · 
72 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: An ultrasonic system with a linear array for characterization of a layered specimen placed in immersion liquid parallel to the aperture of the array is considered. To estimate the longitudinal and transverse wave velocities as well as the thickness and density of the specimen, it is proposed to decompose the spatio-temporal data recorded by the array in a spectrum of plane pulse waves. Based on fitting the developed wave model of the system to the experimental data, it is shown that the relative delays and amplitudes of the spectral responses can be used for the estimation of the velocities and thickness of the layer and its density. The distortions of the plane wave spectrum caused by the spatial discretization of the array data are considered. It is proposed to suppress these distortions using individual interpolating processing of the received pulses separated in the spatio-temporal domain. The developed technique is experimentally verified on a fused quartz plate evaluated with a 17-MHz linear array. The relative reproducibility of the estimation is found to be 0.11% in the longitudinal wave velocity and thickness of the plate, and 0.5% and 5% in the transverse wave velocity and the density, respectively.
    IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control 07/2013; 60(7):1435-1445. DOI:10.1109/TUFFC.2013.2715 · 1.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The paper discusses a method for measuring the velocities and attenuation of longitudinal and transverse ultrasonic waves and the density and thickness of the isotropic layer with an array placed in an immersion liquid parallel to the sample. The method is based on the recording of the total spatiotemporal signal of the array and its expansion into a spatial spectrum of pulse plane wave response. The ultrasonic velocity and sample thickness depend on the response delay of the plane wave in the layer from the transverse projection of the slowness vector. The density and attenuation are determined from the behavior of the amplitudes of spectral responses. To confirm this method in experiment, the parameters of a polystyrene plate have been measured using a linear 32-element array with a central frequency of 17 MHz.
    Acoustical Physics 09/2013; 59(5):600-607. DOI:10.1134/S1063771013050163 · 0.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We suggest a new method for determining the longitudinal and transverse acoustic wave velocities and sample thicknesses, which is based on the measurement and analysis of pulsed echo signals by an array of ultrasonic transducers. Analytical expressions relating the delay of signals detected by the array and the values of parameters to be determined are obtained within the framework of a ray model of the measuring system. Measurements on a reference sample have been performed. The values of ultrasonic wave velocities and sample thickness obtained using the proposed technique agree with the results of measurements using independent methods.
    Technical Physics Letters 11/2009; 35(11):1029-1031. DOI:10.1134/S1063785009110170 · 0.58 Impact Factor