Biomedical Engineering Reference
In-Depth Information
Fig. 2.1 Schematic representation of the B
OSS
-Procedure using the example of the interaction
between a B
OSS
-Model and a soft foam mattress
In the method presented here all digitalized data were combined in a numerical
finite element model of the total interacting system, i.e. B
OSS
-Model and tSD,
to analyze tissue stress and strain during complex interaction.
2.2 Experiments with Technical Support Devices
Depending on the particular materials, quasi and/or transient static and dynamic
tensile or compression or shear tests were performed in a defined and repro-
ducible manner, using appropriate material samples. Based on the experimental
results, e.g. force-displacement data, parameter optimization was performed
employing adequate constitutive equations and numerical optimization
algorithms (curve fitting). Where a 3 D stress and strain state under loading is
indispensable, e.g. due to extensive lateral straining of the sample, the process of
material parameter identification must be accompanied by finite element
modeling of the experimental scenario (inverse FEM). In addition, material
exhibiting distinct viscoelastic features must either undergo an experimental
procedure capable of separating the elastic from the inelastic material properties,
or an appropriate material model must be primarily employed, not requiring such
