Determination of mechanical properties of soft tissue by rolling indentation, digital image correlation and finite element modelling
Institut für Technische Optik, Universität Stuttgart; 2 Institut für Materialprüfung, Werkstoffkunde und Festigkeitslehre, Universität Stuttgart; 3 Institut für angewandte Physik, Universität Tübingen
schumacher@ito.uni-stuttgart.de
Abstract
The measurement of mechanical properties of soft tissue offers new and promising possibilities to discriminate pathological from healthy tissue. Due to the limitation of available human tissue a silicon phantom with similar mechanical features as human tissue (kidney) was manufactured. Cancerous tissue can be mimicked by using a mixture of hard and soft silicon. Applying a known force with a roll-indenter to the phantom combined with digital acquisition and image correlation a 2D-displacement field, showing the mechanical behavior of the phantom, can be obtained. The displacement field in combination with the stress-strain curve of the material is investigated using a finite element model (Arruda-Boyce), in order to obtain the 2D distribution of its elasticity parameters (locking stretch & shear modulus). 3D FE simulations based on this model are in good agreement with the experimental results. Further simulations have been developed to predict the mechanical behavior of different inclusions in the tissue.