Abstract

Speaker: Tara Venkatadri

Title: Effect of Prestress on the Bistability of Deployable Hinges

Abstract:

Bistable hinges are structures that can be snapped between two stable states, often harnessing a mechanical instability such as buckling, by the application of a transient load. This study examined two geometries of bistable hinges: a bending hinge based on the von Mises truss, and a twisting hinge with two plates connected by angled rods. Prestress was introduced into these structures through a combination of 3D-printed prototypes, mathematical theory, and finite element models, and its effect on stability was characterized. It was found that prestress may be used to tune the range of displacement or rotation between the two stable states, but that too much prestress would suppress bistability. The results from this study may be applied in the future to create lightweight deployment systems for large spacecraft structures.

Speaker:James Whiteley

Title: Design of optimized reinforced concrete floor grillages

Abstract:

A new lightweight reinforced concrete beam grillage floor is proposed, whose topology is found via numerical layout optimization. The depths and reinforcement of downstand beams are tailored to local strength requirements, and material savings relative to single-bay flat slabs of 40-50% were calculated. Parametric studies were conducted on multi-bay floorplates, finding that optimal grillage volumes could be decreased by approximately 50% by changing the locations of supporting columns. The system presents challenges in terms of architectural design and fabrication, which could be the subject of future work.

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Meeting ID: 837 2933 8532