Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, September, 2020
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2021
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| Online Access: | https://hdl.handle.net/1721.1/129015 |
| _version_ | 1826194898553929728 |
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| author | Sun, Shiyao,M. Eng.Massachusetts Institute of Technology. |
| author2 | Josephine V. Carstensen. |
| author_facet | Josephine V. Carstensen. Sun, Shiyao,M. Eng.Massachusetts Institute of Technology. |
| author_sort | Sun, Shiyao,M. Eng.Massachusetts Institute of Technology. |
| collection | MIT |
| description | Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, September, 2020 |
| first_indexed | 2024-09-23T10:03:55Z |
| format | Thesis |
| id | mit-1721.1/129015 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T10:03:55Z |
| publishDate | 2021 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1290152021-01-06T04:07:56Z Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis Sun, Shiyao,M. Eng.Massachusetts Institute of Technology. Josephine V. Carstensen. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Civil and Environmental Engineering. Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, September, 2020 Cataloged from student-submitted PDF of thesis. Includes bibliographical references (pages 55-58). Deployable structures, known for their flexibility and adaptability, have gained popularity in applications such as emergency shelters, aerospace structures, and sports facility roofs. One of many commonly used deployable mechanisms is Scissor-Like Elements, which is generally made from two straight rods connected by a scissor hinge. To improve the quality of the flexibility, deployable scissor structures must be lightweight. This thesis will use topology optimization, a free-form design technology, to design low-weight rods within chains of deployable scissor elements. This will be done with the aim of finding a trade-off relationship between the structural performance and the required energy for the deployment of scissor chains. From the trade-off relationship, the balance between the structural stiffness, material saving, and power saving is investigated. The first segment of the study focuses on reducing the self-weight of a deployable scissor chain while ensuring its structural performance through topology optimization. The scissor chain, intended as a retractable roof component, is formed by three pairs of scissors made of two identical bars with homogeneous steel material. Topology optimization tasks with varying volume constraints (50-90%) are performed in Abaqus on the static scissor chain in its open state. To avoid support condition influence, only the scissor bars in the center pair are optimized. The resulting topology-optimized bar geometries are found to have resemblance to hollow core sections. The second part of the thesis establishes the nonlinear force-displacement relationship of the deployable scissor chain and the structural performance of the deployed structure. The topology-optimized center scissor pair is extracted and postprocessed to form a chain with three identical optimized scissor pairs in closed position. Using nonlinear analysis, this structure is computationally deployed to its fully open state. The resulting nonlinear external force required for deployment is recorded. A similar nonlinear force-displacement pattern is discovered in all cases. Furthermore, the total energy required to fully deploy the structure is calculated. Interestingly, both the maximum force and the total energy are found to increase nearly linearly with increasing self-weight. The structural performance of each case is studied by determining the center deflection under a service load. The weight reduction is found to affect the stiffness, with the 50% design showing a drastic reduction compared to the unoptimized case. The stiffness sacrifice decreases with weight reduction such that the 80% and 90% cases experience only mild decreases compared to the unoptimized chain. By comparison of the weight-deflection and the weight-energy to deploy relationships, the study illustrates a trade-off relationship. An ideal point for the case study in this work seems to appear between 60% and 80% volume limits, where the required external work for deployment is reduced by more than 36.8% while the deflection is only increased by less than 22.4% compared to the reference (V=100%V₀). by Shiyao Sun. M. Eng. M.Eng. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering 2021-01-05T23:13:03Z 2021-01-05T23:13:03Z 2020 2020 Thesis https://hdl.handle.net/1721.1/129015 1227046065 eng MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided. http://dspace.mit.edu/handle/1721.1/7582 58 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Civil and Environmental Engineering. Sun, Shiyao,M. Eng.Massachusetts Institute of Technology. Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis |
| title | Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis |
| title_full | Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis |
| title_fullStr | Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis |
| title_full_unstemmed | Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis |
| title_short | Nonlinear analysis of topology-optimized scissor-like elements during deployment and structural performance analysis |
| title_sort | nonlinear analysis of topology optimized scissor like elements during deployment and structural performance analysis |
| topic | Civil and Environmental Engineering. |
| url | https://hdl.handle.net/1721.1/129015 |
| work_keys_str_mv | AT sunshiyaomengmassachusettsinstituteoftechnology nonlinearanalysisoftopologyoptimizedscissorlikeelementsduringdeploymentandstructuralperformanceanalysis |