Abstract

The Influence of a Strong Acoustic CW Wave on Week Resonances in Rock

I.A.Soustova (Department of Hydrophysics and Hydroacoustic, Institute of Applied Physics Russian Academy of Sciences, Nizhny Novgorod, Russia)

e-mail: soustova@hydro.appl.sci-nnov.ru

The influence of a strong acoustic wave on a weak probe wave can be used as one of the methods of the Nonlinear Resonance Acoustic Spectroscopy (NRUS). The technique is based on measurements of the resonance frequencies and quality factors (applying linear resonant ultrasound spectroscopy) for a relatively weak probe wave in the presence of a strong CW pump wave. The theory describing a shift of the resonance frequency and the increasing of Q- factor for high frequency probe wave in the presence of the low frequency strong pump wave is the topic of this presentation. The model is based on including small hysteretic loops in stress-strain dependence for the probe wave. The hysteretic loop parameters dependence on the loop position on the stress-strain dependence for the pump wave. The developed theory is used to explain experiments with concrete and sandstone conducted by Dr. A.Sutin in Los Alamos National Laboratory. (The work was supported by RFFI grant 00-05-64252).

Section : 3