Design of an aluminum plate-based tensegrity bike parking canopy

Gathman, Heather Faith

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https://hdl.handle.net/2142/115623 Copy

Description

Title

Design of an aluminum plate-based tensegrity bike parking canopy

Author(s)

Gathman, Heather Faith

Issue Date

2022-04-28

Director of Research (if dissertation) or Advisor (if thesis)

Sychterz, Ann C

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

tensegrity, plate based tensegrity, aluminum, dynamic relaxation, full-scale structure, structural design

Abstract

Adaptive and lightweight structures have increasingly become an area of interest to researchers and engineers, leading to the continued development of the design and analysis of tensegrity structures. Tensegrity structures are composed of bars and cables and are stabilized by self-stress. They have a high strength-to-weight ratio and can be useful as adaptive and modular structures. However, current research on tensegrity structures in civil engineering applications has largely neglected incorporating necessary surface elements, such as bridge decks or roof coverings, into the tensegrity structure. In an effort to increase the utility of tensegrity structures in civil engineering, this thesis describes the design development and analysis of a full-scale aluminum plate-based tensegrity canopy structure, which introduces a plate as a third element type. To date, the concept of plate-based tensegrity has not yet been implemented in a full scale structure and few analysis methods have been proposed. The proposed structure will be built as a bike parking canopy on the University of Illinois Urbana-Champaign’s campus. Dynamic relaxation is a static solution of form-finding that is useful for tensegrity structures and is the analysis method considered in this work. Design of the roof structure includes evaluation of several load cases from current U.S. design criteria. Results indicate that plate tensegrity structures can meet current civil engineering criteria for strength and serviceability. In addition to static analysis, there are other design considerations which must be assessed. Namely, self-stress state determination to ensure a stable configuration and dynamic characterization to ensure resistance to vibrations induced by wind and seismic activity. From a finite element model of the structure, the first five mode shapes and eigenfrequencies are obtained. Results show that eigenfrequencies are sufficiently high to be beyond the risk of resonance for wind and seismic activity. The number of self-stress states for a single module and full-scale roof is also determined through the construction of the equilibrium matrix. The existence of multiple self-stress states indicates a stable configuration of the structure. Lastly, joint designs are proposed in this work and documentation for preliminary assembly is outlined. Results of this thesis will further advance the practical design and construction of plate-based tensegrity structures and serve as a display of the feasibility of building large scale tensegrity structures.

Graduation Semester

2022-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Heather Gathman

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