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This and the next several slides show results for optimized CYLINDRICAL balloons.
The true prismatic formulation in BIGBOSOR4 is used for modeling the cylindrical balloons.
This is Fig. 56 from the 2012 GENOPT paper. This slide shows the weight/length of optimized cylindrical balloons made of carbon fiber cloth as a function of the number of modules over 90 degrees of circumference.
All of the results in this figure were obtained with models in which there are 31 nodal points in each segment of the multi-module model. For the models with truss-like webs there are six segments per module plus two additional segments near the circumferential coordinate, 90 degrees (Fig. 4 of the 2012 GENOPT paper). For models with radial webs there are five segments per module plus four additional segments near 90 degrees (Fig.3 of the 2012 GENOPT paper).
BIGBOSOR4 can handle up to 45 modules for models with truss-like webs and up to 55 modules for models with radial webs.
For models with large numbers of modules the number of nodal points per segment is limited by the total number of degrees of freedom permitted by BIGBOSOR4 for pre-buckling analysis (20000 d.o.f) and for bifurcation buckling analysis (30000 d.o.f.).
Compare this figure with Fig. 25 of [1] (Reference 1 listed in the References section of the 2012 GENOPT paper). The optimized balloons made of carbon fiber cloth are about a factor of 17 lighter than those made of polyethylene terephthalate.
For viewing figures and tables referred to here but not shown here, please download the 2012 GENOPT paper from this website.
Reference for the "true prismatic" shell model incorporated recently (2010) into BIGBOSOR4:
Bushnell, David, "Comparison of a "huge torus" model with a true prismatic model for: 1. an axially compressed simple monocoque cylindrical shell, 2. an axially compressed optimized truss-core sandwich cylindrical shell, and 3. an axially compressed optimized internally ring and stringer stiffened cylindrical shell with a T-stiffened weld land, Unpublished report for NASA Langley Research Center, February 12, 2010 and contained in the file, ...bigbosor4/case/prismatic/prismaticshell.pdf
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