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

The centers of the simulated cells were separated by 200 µm, e.g., 13.3 cell diameters.
The void on the left (when viewed along the z-axis through the thickness) simulated a
contracting cell (with a prescribed displacement to decrease the radius by 2 µm); the
void on the right had its boundary surfaces held fixed; all other boundaries were free.
Fig 2. Idealized cell and fiber geometry used for the computer models.
Three fibers, Fiber 1, Fiber 6, and Fiber 10 were identified as potentially key fibers for
connections between the two simulated cells, see Fig. 3a. Fig 3.b shows a typical finite
element mesh made semi-transparent to see influence of embedded fibers on the mesh.
a. b.
Fig 3. Semi-transparent plots viewed along the z-axis. The left circular void represents
the contracting cell; the right circular void is fixed. a) Fiber arrangement, with the 3
labeled fibers chosen for testing the influence of entanglement (Fiber 1, 6, and 10). b)
The finite element mesh with 10-noded tetrahedral elements, with approximately 3.5
million degrees-of-freedom.
Three cases were generated for analysis.
• Case 1: Tangled Fibers. To simulate the extreme case – all fibers that connect
are cross-linked (tangled) -- the fibers were all centered in a plane, z = 0, in the
middle of the matrix material.
• Case 2: No Fibers. To simulate the effect of cell contraction in the opposite
extreme case – with no fibers interacting – the Case 1 mesh was used, but the
properties of the fibers were decreased to match that of the surrounding matrix
material.