Cavitation in inhomogeneous soft solids

Abstract

A tiny spherical cavity expands in a homogenous neo-Hookean solid when subjected to an externally applied hydrostatic tension. If the applied tension reaches 2.5 times the shear modulus of the solid, the cavity expands unboundedly. Such a phenomenon is usually referred to as cavitation in soft solids. In previous studies, the soft solid is often assumed to have homogeneous mechanical properties. In this article, we study cavity expansion in inhomogeneous soft solids through analytical formulation and finite element simulations. We find that cavitation in an inhomogeneous soft solid can be greatly different from that in a homogenous one. In particular, we show that the relationship between the applied hydrostatic tension and the cavity size can be either monotonic or non-monotonic, depending on the geometry and material properties of the soft solid. We hope the results obtained in this article will be helpful in understanding the cavitation phenomenon in complex soft materials.