Modeling of indentation into inhomogeneous soft tissues

A simulation of a contact interaction of the indenter and inhomogeneous soft biological tissues is carried out. The soft tissue is modeled by the incompressible elastic body which contains structural inhomogeneities (spherical or longitudinal inclusions). The elastic moduli of inclusions are higher than the bulk soft tissue modulus. These inclusions may be considered, in particular, as the models of the pathological growths. The indenter has the form of a hollow hemisphere (shell). It is the model of the mechanoreceptor developed in [1] to study the mechanical properties of soft tissues. The hydrostatic pressure can be applied inside the shell. Based on the numerical analysis, the dependences of the contact area size, and contact pressure on penetration of the indenter into the sample for several values of the inclusion size, depth, its location, the ratio of the elastic moduli of inclusion and the surrounding material, but also for various values of hydrostatic pressure inside the shell were obtained. The possibility of an inverse problem solution for determining the mechanical properties of the inclusion, and its size by measuring the contact characteristics is discussed.