含流体夹杂弹性介质有效性能

Study on Effective Properties of Elastic Media Containing Fluid Inclusions

为了研究流体内压对闭孔材料有效性能的影响,采用细观力学方法,建立了含有内压流体的细观力学模型,用以分析孔压与材料宏观变形的耦合效应.流体和内压通过等效特征应变来表征,将Eshelby-Mori-Tanaka等效夹杂原理推广到含流体夹杂的材料有效性能问题中,得到了含流体夹杂弹性介质有效刚度的解析式.比较解析解与有限元数值结果可知二者吻合较好.研究表明,材料的有效体积模量与流体夹杂性能、体分比及内压有关,且流体内压能显著提高材料的有效体积模量,而有效剪切模量与流体性能及内压无关.

To examine the effects of fluid pressure on effective properties of solids with closed pores, a new micromechanical model has been developed to investigate the coupling effect between the macroscopic deformation and the pore pressure. In the proposed micromechanical model, the internal pressure is generated by applying eigenstrain in the domain occupied by the fluid phase. The effective properties have been obtained with the use of Eshelby-Mori-Tanaka equivalent inclusion method. Analytical results are verified against those from finite element solutions and a good agreement is achieved. The results show the overall effective bulk modulus depends on the property, the volume fraction and the internal pressure of fluid inclusions. The fluid pressure can strengthen the overall effective bulk modulus, but it has no contribution to the overall effective shear modulus.