Structural lightening is a recurring challenge in engineering. The will to reduce energy consumption, increase carrying capacity, or improve performance are all reasons to aim for ever more optimized designs. Micro-lattices, with their extreme thinness, bring this quest to the smallest scales of additive manufacturing. With this subject, the idea is to connect design with the mechanical performance of polymer micro-lattice structures using small aerostats as the working platform. Besides the new opportunities offered by the development of this type of aircraft, airships have the particularity of being extremely sensitive to the mass of their components. No compromise is allowed, and every new gram is an additional liter of helium to be added. This requirement makes aerostats the ideal testing base for seeking new solutions to optimize mass.
First, several additive manufacturing techniques based on photosensitive resinswere mechanically studied using quasi-static micro-tension tests on micro-lattices structures. The tests were associated with full-field deformation measurements. The processes were also the subject of a study on the anisotropy of manufacturing to better understand their impact on the mechanical properties of micro-lattices.
Secondly, a multi-criteria prioritization methodology is presented. This tool allows understanding and visualizing the impact of each requirement of a complex specification on the choice of the final combination. It helps to rationalize decision-making regardless of metrics and domains : mechanical criteria, manufacturing, shape, etc. An airship is a complex physical object, and this method accelerates the development process.
Thirdly, micro-lattice structures were characterized for their impact energy absorption properties. For this purpose, a test bench was specially designed and manufactured to adapt to the flight conditions of a lightweight indoor aircraft. The results were used to select the patterns, materials, and compacity required to meet the operational requirements of the aerostat.
Finally, this work concludes with the design, manufacturing and assembly of a rigid but foldable robotic airship adapted for exploring narrow spaces. It incorporates an exoskeleton inspired by origami to provide unique properties to the aerostats. The robot design process was automated to optimize its shape according to all intertwined constraints of volume, manufacturing or mechatronics
| Date | 7 Nov 2024 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | David St-Onge (Supervisor) & Ilyass Tabiai (Co-supervisor) |
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Catar, L. (Author),
St-Onge (Supervisor) &
Tabiai (Co-supervisor),
7 Nov 2024Student thesis: Doctoral thesis › Doctorate in Engineering: Engineering