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6.4 Inflation of a Balloon
Finite Element Analysis of Membrane Structures 65
Fig. 8. Deformed configuration of membrane
The fourth problem represents the inflation of a balloon and is presented to test the
performance of the triangular membrane element and solution strategy onavery
non-linear problem. The mesh geometry consists on two flat, horizontal surfaces
connected to a vertical conical open end. Figure 9 shows the geometry of a balloon
in its uninflated state. An internal pressure (follower) loading of 5 units is applied
to bring the balloon to a finalverticalconfiguration. The circular end of the cone
has all its degrees of freedom fixed. The parameters for the material are
E = 1000 ; ν =0.25 ; ρ0 =10 ; he = 0.1
Fig. 9. Reference configuration of the balloon
DISPLACEMENT 1
-2.00E+00
-1.71E+00
-1.43E+00
-1.14E+00
-8.55E-01
-5.69E-01
-2.83E-01
3.27E-03