Finite Element Design and Modal Analysis of a Hexakis Icosahedron Frame for Use in a Vacuum Lighter-Than-Air Vehicle
Publication: Journal of Engineering Mechanics
Volume 144, Issue 6
Abstract
This research discusses the design, modal analysis, and additive manufacturing of a hexakis icosahedron frame for use in a vacuum lighter-than-air vehicle (VLTAV). A frame in the shape of a hexakis icosahedron, when encased by a thin membrane-like skin, would be able to withstand the pressure load induced by internal air evacuation and produce positive buoyancy. For a better appreciation of the force resistance within the hexakis frame, a manufactured frame was constructed. The actual frame has many varying oriented beams, making its construction complicated for standard production methods. Therefore, additive manufacturing was incorporated. A portion of this paper is directed toward the description of the method carried out. A 0.1778-m-diameter hexakis icosahedron frame was additively manufactured using VeroWhitePlus plastic. A modal experiment using a laser vibrometer was performed in order to determine the eigenvalues of the structure for comparison to the modal analysis results of a finite element (FE) model of the frame assuming a free-free boundary condition. This comparison allowed for the verification of the equivalent modulus of elasticity used in an analysis and the overall construction of the model. The finite element model predicted the first two frequency modes within 1% of the experimental results. Because the FE model accurately predicted the dynamic properties of the frame, the modeling technique in which the assumed member connections were verified led to confidence for future modeling.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to thank the Air Force Office of Scientific Research (AFOSR) for their financial support in particular Mr. Fillerup monitored the research.
References
Adorno-Rodriguez, R. 2014. “Nonlinear structural analysis of an icosahedron and its application to lighter than air vehicles under a vacuum.” Master’s thesis, Greene County, OH: Dept. of Aeronautics and Astronautics, Air Force Institute of Technology, WPAFB.
Adorno-Rodriguez, R., and A. Palazotto. 2015. “Nonlinear structural analysis of an icosahedron under an internal vacuum.” J. Aircr. 52 (3): 878–883.
Barclift, M., and C. Williams. 2012. “Examining variability in the mechanical properties of parts manufactured via polyjet direct 3D printing.” In Int. Solid Freeform Fabrication Symp., 6–8. Austin, TX: Univ. of Texas.
Cranston, B. 2016. “Conceptual design, structural analysis, and design space exploration of a vacuum lighter than air vehicle.” Ph.D. dissertation, Greene County, OH: Dept. of Aeronautics and Astronautics, Air Force Institute of Technology, WPAFB.
Cranston, B., M. Alghofaily, and A. Palazotto. 2017. “Design and structural analysis of a unique structure under an internal vacuum.” Aerosp. Sci. Technol. 68: 68–76.
Dassault Systèmes. 2014. Abaqus analysis user’s manual. St. Providence, RI.
Just, L. 2015. “Dynamic response analysis of an icosahedron shaped lighter than air vehicle.” Master’s thesis, Greene County, OH: Dept. of Aeronautics and Astronautics, Air Force Institute of Technology, WPAFB.
Just, L., A. Deluca, and A. Palazotto. 2017. “Nonlinear dynamic analysis of an icosahedron frame which exhibits chaotic behavior.” J. Comput. Nonlinear Dyn. 12 (1), 011006.
Kashef, A. 2012. “Tutorial—How to import points to solidworks from a text file.” Accessed November 15, 2016. https://www.bing.com/videos/search?q=to%20find%20+how+to+import+points+from+text+file.
Metlen, T. 2013. “Design of a lighter than air vehicle that achieves positive buoyancy in air using a vacuum.” Master’s thesis, Air Force Institute of Technology.
Metlen, T., A. Palazotto, and B. Cranston. 2016. “Economic optimization of cargo airships.” CEAS Aeronaut. J. 7 (2): 287–298.
Noel, D. 1983. “Lighter than air craft using vacuum.” Correspondence, Speculations Sci. Technol. 6 (3): 262–266.
Stratasys. 2016. Color and multi-material 3D printing: Objet500 and Objet350 Connex3. St. Providence, RI.
Information & Authors
Information
Published In
Copyright
©2018 American Society of Civil Engineers.
History
Received: Aug 8, 2017
Accepted: Dec 13, 2017
Published online: Apr 13, 2018
Published in print: Jun 1, 2018
Discussion open until: Sep 13, 2018
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.