In vitro compression of a soft tissue layer on a rigid foundation

In vitro compression studies have been performed on layers of porcine skin and fat. The tissue layers have been loaded by means of various indentors. Indentor displacements and interstitial fluid pressures have been measured. The results have been compared to finite element calculations with mixture elements. A qualitative agreement between calculations and measurements is found. The results support the hypothesis that skin and fat behave like solid/fluid mixtures

Optimization of experiments for the identification of material parameters in computational models

The identifiability problem that rises in mixed numerical-experimental problems is one of the most important issues if an experiment has to be designed for the quantification of material parameters. This paper focuses on the relation between various aspects of an experiment and the condition number of the information matrix used in gradient algorithms for the parameter estimation. The initial estimate of the parameter sets permits to indicate whether or not the designed experiment provides the required information. A comparison is made for a tensile specimen and a bend specimen, where different types of measurements are simulated. Various aspects influence the optimal relation between an experiment and a numerical model. The proper analysis of this relationship permits the optimization of the design of an experimen