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

Pressure k Pa
700.0
600.0
500.0
400.0
300.0
200.0
100.0
Pressure kPa Resin Pressure kPa Total Pressure Required Lam Top Surface Height m
0.0
0.00100
0 60 120 180 240 300 360 420 480 540 600
time secs
36
0.00240
0.00220
0.00200
0.00180
0.00160
0.00140
0.00120
Figure 3.7. Flat Laminate Model Constant Pressure Dwell with Permeability as a Function
of Vf.
there was no further compaction movement. Changes in Vf required significant increases in
Pappl to continue compaction.
3.12 The Flexbeam Laminate Model Geometry, Control Volumes and Nodes
The laminate is modeled as a 2+1/2 dimensional body having length x and height z
dimensions with a constant depth dy. The laminate interior volume is subdivided into n x n
control volumes (CVs), and 2n additional CVs for its exterior, each possessing resin volume and
fiber volume and assuming negligible void volume. For each position x separated by dx, the
laminate top surface height is divided into n CV heights, so the height of a CV differs with
differences in the laminate height.
Figure 3.8 portrays the CVs and nodes within a simple flat laminate. The sum of all
CVs’ resin and fiber volume represents the overall laminate during the cure process. The 2D
geometry of a CV is defined to be rectangular (x width, z height, and dy depth). Two nodes are
associated with each CV. The top node (blue) monitors its top surface (z) height due to
compaction and contact. The other node (yellow) defines its mid-width and mid-height (z)
position and is used for determining resin flow velocity and temperature estimating. Interior
Height m