共振声谱法低频岩石声学特性测量方法研究

On the basis of theoretical analysis, the acoustic frequencies of enclosed resonant spherical and cylindrical cavities with an inner eccentric sphere and an inner coaxial sample cylinder are calculated. The effect of velocity, density, characteristic impedance, geometry of the sample on acoustic resonant frequency is reviewed. The experimental scheme is put forward and the measure system comprised of amplifier lock in phase, power amplifier, charge amplifier and resonant cylindrical cavity is set up. Acoustic frequencies measured are compared with those calculated in theory. Based on the theoretical analysis and experimental measure, two methods to get acoustic frequency of the sample are put forward. It shows that the method of using acoustic resonance spectroscopy to measure the acoustic velocity of rock is feasible. In addition, elementary research on acoustic resonance spectroscopy in a fluid-filled borehole is done.

利用微扰理论和边界元法分析计算封闭圆柱形和球形共振腔体中具有小扰动体时的共振声谱及其影响因素，寻找岩样的声速与衰减等和共振声谱关系。从理论和实验角度研究利用共振声谱法测量低频岩石（包括强耗散、非均质甚至不规则岩样）声速与衰减的原理与方法。该课题有较大的理论价值和较强的应用背景。