Effective elastic modulus of wet granular materials derived from modified effective medium approximation and proposal of an equation for the friction coefficient between the object and wet granular materials surfaces.

Liefferink et al. (GM 22: 57, 2020) reported the effect of liquid volume fraction on the penetration hardness/shear modulus and the friction coefficient of several types of wet sand. However, no analytical equation can simultaneously explain these two observations. In this paper, we formulate the effective elastic modulus of wet granular material as a function of the liquid volume fraction using the effective medium approximation. We also propose the equation of the friction coefficient between the surface of an object and the surface of the wet granular materials. The equations for the modulus of elasticity and coefficient of friction as a function of the liquid volume fraction can well explain the observed data by using a few adjusted parameters. [ABSTRACT FROM AUTHOR]