Two-Phase Model for Fluid-Saturated Porous Media

摘要

Three-dimensional two-phase models, for analyzing the problems of stress wave propagation in fluid-saturated porous media, are proposed by introducing the fluid-solid coupling concept. The difference for two-phase models proposed here to the usually used theories for wave propagation in fluid-saturated porous media is that the investigated object is the true structure of the fluid-saturated porous media, instead of the substitutive models. Adopting direct coupling technique, a three-dimensional fluid-solid mixture explicit dynamic finite element scheme is developed. Three-dimensional stress wave propagation in the fluid-saturated porous media due to impact loading is numerically simulated. The present results show that the wave speeds obtained by our models accord well with the speeds given by Biot' s theory, but our models can further reflect the influence of the local structure of the porous media on the propagation characteristic of the stress waves. Moreover, the effects of the porosity and the shapes of the pores on the propagation characteristic of the main waves are discussed in detail.