Presenter(s): Daniel Sellers—Physics
Faculty Mentor(s): Ben McMorran
Session: Prerecorded Poster Presentation
The ultimate expression of Archimedes’ principle of buoyancy would be to enclose a vacuum with some structure of less mass than the air displaced by that structure . So far such a craft has never been realized in prototype due to the daunting material and engineering challenges . We propose a novel design for such an airship, using inflatable supports and an Aramid fabric shell, and examine the physical constraints and material requirements using both SolidWorks (SW) Simulation Finite Element Analysis and principles of structural statics .
We develop a dynamic simulator (in python) to approximate the shapes formed by thin fabric shell sections under unbalanced pressure loads . The resulting geometries are converted to thin shell SolidWorks models and analyzed . Attempts are made to verify the results, including mesh independence and comparison to empirical stress/strain results performed on similar materials and configurations .
Deflection of thin shell sections using material properties of Kevlar Aramid fiber are found to agree qualitatively with the theoretical results of Timeshemko, though actual deflection predicted by SW is marginally smaller than predicted by theory, which in turn only very roughly agrees with the experimental results considered . The tensile stress within the shell models is found to be well within acceptable limits for typical Aramid fibers . Some models for the inflatable support structure currently under development are presented, without results . The advantages and challenges of the Finite Element Method for novel design concepts are briefly discussed .