Structural Analysis of the Hexakis Icosahedron Lighter Than Air Vehicle and the Air Evacuation System

摘要

The research this paper focuses on is comparing the structural differences between the icosahedron and hexakis icosahedron frame and skin for use as a vacuum lighter than air vehicle (VLTAV), analyzing the stress concentrations in the hexakis icosahedron both with and without the skin, and finding the optimal location and size of the air evacuation method for creating the internal vacuum. Findings demonstrated that the hexakis icosahedron resisted collapse significantly when compared to the icosahedron, and the W/B ratio of the hexakis icosahedron was smaller for the same structural and material characterizations. The hexakis-icosahedron came the closest to the yield stress of the material in the frame consisting of the Carbon-Nanotube (CNT) composite at 3.38 GPa, with the yield stress being 3.8 GPa. The minimum stress in the beams for the top and bottom points of the structure was found to be at approximately 20% and 66% of the beam length. Placing small holes for air evacuation resulted in minimal stress changes for the entrance to the evacuation system, but created failure points at the top and bottom of the structure, where the exit to the air evacuation system was located. Adding material to the exit system solved the failure point and kept the stress levels below yielding.