On thermodynamics of elasto-plastic porous media

The paper concerns a macroscopic description of fluid-saturated porous media via mixture theories extended by the volume fraction concept. Proceeding from second-grade materials, elasto-plasticity is taken into account by means of a multiplicative decompositon of the first and second solid deformation gradient. The constitutive theory is discussed on the basis of the example of an immiscible binary model consisting of an elasto-plastic solid matrix saturated by one viscous liquid