TOOLED THICK COMPOSITES by ARVEN H. SAUNDERS III ...

• Resin pressure causes resin flow and increases in VF. Each CV may differ in VF
depending on how much net flow out has occurred.
• Resin pressure will decline when Pappl is not monotonically increasing, using a
pressure film approach.
• The flat laminate flow properties can be extended or apply as well to contact areas—
i.e., same total flow volume rate and distribution of resin pressures.
In summary, the solution via the Kirchoff algorithm for resin flow rates and resin
pressures at the nodes/junctions is based on the flat laminate mode. A rigid lid surface imposes
uniform pressure across the laminate top surface causing resin flow. All laminate volume is
assumed to consist of fibers fully saturated with resin, with negligible void volume. Resin volume
flowing out the sides is contributed equally by all sectors of laminate resin volume. Therefore,
assuming homogeneous material properties throughout, resin pressure ranges from zero at
edges to Pmax at the center.
3.23 Flow Chart/Sequence for the Flexbeam Model
1. Setup model, initialize variables, definition of laminate CVs and nodes, material properties,
etc.
2. Define initial location of laminate surfaces and lid surfaces; determine contact (true/false).
3. Set current time, read current cure cycle conditions- including force.
4. Update model status- update laminate heights, resin volumes, VF, node locations, lid
position. Update contact status of each CV.
5. Determine flow heights for all CVs – update based on changes to heights from change in
resin volumes. Then using this value as input, determine flow resistance values HR and VR.
VR for flow out top of top level CVs is dependent on contact or not.
6. Define contact area(s) and mid-contact area CVs for Pmax determination-- based on
current contact areas, set holder for Pmax value for the mid- contact area CVs- this
includes setting single CV for odd numbered CVs within a contact area, or setting up 2 mid-
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