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

Figure 4 - Correlation between FE and experimental results as bridge and sheath stiffness varies relative to lamellar
stiffness. Value “-1” on the horizontal axis refers to a lamellar/bridge stiffness ratio of 1:0.1, value “2” refers to the
ratio 1:100 and value “5” refers to ratio 1:100,000.
For the bridge model, there was very little change in the correlation of the FE results
with the experimental data, as shown in Figure 4. Although a marked change in
boundary shape was seen in Figure 3, as the bridges are only acting on the internal
boundaries in concentrated areas, these become averaged out over the whole length of
the boundary when the correlation is considered.
A slight improvement was seen in the correlation between the sheath model and the
experimental data as the stiffness of the sheath increased. This however does not
necessarily indicate that the model is becoming more accurate. Because the sheath
elements are acting along the entire length of the boundary, as their stiffness increases
the model becomes stabilised. The shape of the deformed boundary is smoother and
overall closer to the experimental data. This does not necessarily mean the
characteristic deformation of the experimental deformation has been more accurately
represented.
5. DISCUSSION
The experimental study presented used similar methodologies to those employed by
Pezowicz et al. 4 . Some similar observations were also recorded. In particular,
throughout the test samples, images showed the cross bridges remained taut whilst the
surrounding tissue constituents strained and deformed more, causing the interlamellar
boundary to pucker. The greater resistance of the bridges to the strain applied implies
that the material properties of the bridges differ to those of the surrounding tissues.
These experimental observations suggest that the structure of the cross bridge network
aids the resistance of the tissue to delamination.
The computational model was built from only one specimen. More models could be
created from more specimens to build greater confidence in the findings. The
computational study has allowed the characteristic deformations of the tissue observed
during the experimental study to be captured in a simulation that facilitates detailed