Anisotropic elastic properties of montmorillonite with different layer charge locations and densities by molecular dynamic simulation

Abstract

Summary This paper has studied the elastic coefficients of montmorillonites (MMT) with different charge locations and densities under stratigraphic conditions using molecular dynamic simulations. (1) The inplane compressional coefficients C11, C22 and C12 decrease with increasing layer charge density in the MMTs with different layer charge locations. (2) The out-of-plane compressional coefficient C33 shows different trends with increasing layer charge density in the MMTs with different layer charge locations. C33 decreases overall with the increasing layer charge density when the layer charge location is on the two tetrahedral (T) sheets, whereas C33 shows an increasing trend with layer charge density when the layer charge location is distributed on the octahedral (O) sheet. For the MMTs with the layer charge location distributed on both the octahedral (O) sheet and the tetrahedral (T) sheets, the increasing layer charge density shows a weak impact on C33. The variations of C13 and C23 with the layer charge density in the MMTs with different layer charge locations are similar to that of C33. (3) All the shear coefficients C44, C55, and C66 of MMT show no strong correlation with the layer charge density and layer charge location.