Design and structural analysis of unique structures under an internal vacuum

This paper details an experiment that was used to validate the frame deformation of three vacuums lighter than air vehicle finite element models composed of a frame with a skin covering. The experiment consisted of a simplified one directional loading to determine the behavior of a 3D printed frame, which was compared to a corresponding finite element model. A 3D printed icosahedron frame was loaded in compression using a mechanical testing machine to record the load versus displacement of the structure. It was discovered that the material properties of the printed structure were significantly lower than the quoted values from the manufacturer. The modulus property was extracted from the finite element model that best matched the experiment. The behavior of the frame from the experiment shows that the beams do buckle. The model matches the frame buckling and load retention. The feasibility of a vacuum lighter than air vehicle using an icosahedron, hexakis icosahedron, and celestial frame and skin were then analyzed since the method of analysis was proven through the experiment. The icosahedron showed failure due to material limits and the hexakis icosahedron showed definite feasibility using modern material properties.