Mechanical Characterization of Biological Tissue: Finite Element Modeling
Indentation, in addition to the traditional tensile testing, has been widely used for evaluating mechanical properties of hard materials such as metals and bone as well as soft materials like polymer and soft tissues. However, it is difficult to measure the contact area and surface deformation in conventional indentation tests of soft tissue which will bring large errors to the evaluation of the material properties. Also the assumption of isotropic property limited the usage of indentation test in characterizing the nonlinear, anisotropic properties of soft tissue thin film. In this project, 2D and 3D finite element analyses has been carried out to predict hyperelastic material response under indentation and punch tests. A novel indentation test system was developed, which made the direct measurement of local deformation and contact area possible. The apparatus consists of a transparent indenter, a digital microscope, and a computer based control and data acquisition system. The proposed testing system and associated finite element analysis are used to characterize the mechanical properties of multiscale (bulk and thin film) biological tissues.