平面P波在弹性介质和非饱和多孔弹性介质分界面上的传播

使用线性粘滞的多孔弹性介质模型,解决在弹性介质和非饱和多孔弹性介质分界面上平面P波的反射与透射问题,这里的非饱和多孔介质中固体骨架被两种相互耦合的流体(液体和气体)所充满.通过势函数的方法得到了振幅反射系数与振幅透射系数.然后推导得到入射波与反射波、透射波之间能量转换情况.研究发现:用振幅比和能量比所表示的反射系数与透射系数是与入射角度、饱和度、入射频率以及上下层介质的弹性常数有关的方程式.数值计算通过图形的形式表达出来,而且入射角度、频率及饱和度对振幅和能量的反射与透射系数的影响分别进行了讨论.证明了在整个波的传播过程中分界处并没有发生能量的耗散.

Propagation of Plane P-Waves at the Interface Between an Elastic Solid and an Unsaturated Poroelastic Medium

A linear viscoporoelastic model was developed to describe the problem of reflection and transmission of an obliquely incident plane P-wave at an interface between an elastic solid and an unsaturated poroelastic medium in which the solid matrix was filled with two weakly coupled fluids(liquid and gas).The expressions for the amplitude reflection coefficients and amplitude transmission coefficients were derived using the potential method.The present derivation was subsequently applied to study the energy conversions among the incident,reflected and transmitted wave modes.It was found that the reflection coefficients and transmission coefficients in the forms of amplitude ratios and energy ratios are functions of incident angle,liquid saturation,frequency of incident wave and elastic constants of the upper and lower media.The numerical computations are performed graphically,and the effects of the incident angle,frequency and liquid saturation on the amplitude and energy reflection and transmission coefficients are respectively discussed.It was verified that during transmission process there was no energy dissipation at the interface.