ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Figure 2 - Micrographs for tensile test specimen T3, showing the full field of view of the microscope. (a) unloaded,
the box indicates the area of interest later used in FE models, the white arrow indicates a sectioned lamella, the red
arrow indicates an in-plane lamella; (b) loaded to extension of 3mm (51% strain), the white arrows show an example
of a lamellar boundary that has become puckered at the locations at which it intersects the interlamellar bridging
elements. The red arrows indicate areas of lamellae that have thinned.);
4.2 Computational Results
The coordinates of the nodes along the internal boundaries for the FE model in its
deformed state were recorded and compared to the equivalent nodes in the experimental
model. Some typical results are shown in Figure 3.
Figure 3 - Traces of internal boundaries for the bridge and sheath models for variation of bridge/sheath stiffness
relative to the experimental data. The shape of the boundaries change as the material properties of the bridges are
varied. The dashed lines show the experimental results. The orange lines show the model performance with a
compliant bridge/sheath material, the green lines with a stiff bridge/sheath material and the red in the mid range of
bridge/sheath stiffness.
As the stiffness of the bridges increased, they deformed much less than their
surrounding tissues, leading to more pronounced puckering along the internal boundary.
For the sheath model, the puckering of the internal boundaries is not as pronounced as
for the bridge model. The presence of the sheath elements along the entire boundary
results in a more even distribution of displacement.