Shape optimization of a fish-like hyperelastic body vibrating with a swimming mode
In this study, a formulation of the inverse problem to identify the shape of a hyperelastic body in which the vibration mode is similar to the swimming mode of a fish is presented. This research aims to demonstrate the possibility of creating a fish robot that swims with a vibration mode in the wate...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2021-12-01
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| Series: | Mechanical Engineering Journal |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/mej/9/1/9_21-00250/_pdf/-char/en |
| _version_ | 1828134810670858240 |
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| author | Takuya HAYASHI Hideyuki AZEGAMI |
| author_facet | Takuya HAYASHI Hideyuki AZEGAMI |
| author_sort | Takuya HAYASHI |
| collection | DOAJ |
| description | In this study, a formulation of the inverse problem to identify the shape of a hyperelastic body in which the vibration mode is similar to the swimming mode of a fish is presented. This research aims to demonstrate the possibility of creating a fish robot that swims with a vibration mode in the water when excited with a vibration generator embedded in the body. Before this study, Chancharoen et al. attempted to formulate an inverse problem as a shape optimization problem for a linear elastic body without considering water. In this study, a cost function was defined by the squared error norm of the vibration mode and the ideal swimming mode. The result of a numerical example confirmed that the approach decreased the cost function, but the obtained vibration model was different from the ideal one. In contrast, in this study, a hyperelastic body is used to approach the actual movement of a fish. Using this replacement, the finite deformation theory is employed to formulate the periodic vibration of the hyperelastic body. The cost function is formulated using the squared error norm of the finite deformation in the cycle. Its shape derivative is evaluated using the solutions of the periodic vibration problem and its adjoint problem with respect to the cost function. To solve the shape optimization problem, an iterative scheme based on the H1 gradient method for domain variation problems is used. The effectiveness of this approach is illustrated through numerical examples using finite-element models. |
| first_indexed | 2024-04-11T17:39:27Z |
| format | Article |
| id | doaj.art-f2193ee37cfb4df9af6ba2dbc69a8b70 |
| institution | Directory Open Access Journal |
| issn | 2187-9745 |
| language | English |
| last_indexed | 2024-04-11T17:39:27Z |
| publishDate | 2021-12-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Mechanical Engineering Journal |
| spelling | doaj.art-f2193ee37cfb4df9af6ba2dbc69a8b702022-12-22T04:11:32ZengThe Japan Society of Mechanical EngineersMechanical Engineering Journal2187-97452021-12-019121-0025021-0025010.1299/mej.21-00250mejShape optimization of a fish-like hyperelastic body vibrating with a swimming modeTakuya HAYASHI0Hideyuki AZEGAMI1Graduate School of Informatics, Nagoya UniversityGraduate School of Informatics, Nagoya UniversityIn this study, a formulation of the inverse problem to identify the shape of a hyperelastic body in which the vibration mode is similar to the swimming mode of a fish is presented. This research aims to demonstrate the possibility of creating a fish robot that swims with a vibration mode in the water when excited with a vibration generator embedded in the body. Before this study, Chancharoen et al. attempted to formulate an inverse problem as a shape optimization problem for a linear elastic body without considering water. In this study, a cost function was defined by the squared error norm of the vibration mode and the ideal swimming mode. The result of a numerical example confirmed that the approach decreased the cost function, but the obtained vibration model was different from the ideal one. In contrast, in this study, a hyperelastic body is used to approach the actual movement of a fish. Using this replacement, the finite deformation theory is employed to formulate the periodic vibration of the hyperelastic body. The cost function is formulated using the squared error norm of the finite deformation in the cycle. Its shape derivative is evaluated using the solutions of the periodic vibration problem and its adjoint problem with respect to the cost function. To solve the shape optimization problem, an iterative scheme based on the H1 gradient method for domain variation problems is used. The effectiveness of this approach is illustrated through numerical examples using finite-element models.https://www.jstage.jst.go.jp/article/mej/9/1/9_21-00250/_pdf/-char/enshape optimizationinverse problemvibration modehyperelastic bodyfinite deformation theoryh1 gradient method |
| spellingShingle | Takuya HAYASHI Hideyuki AZEGAMI Shape optimization of a fish-like hyperelastic body vibrating with a swimming mode Mechanical Engineering Journal shape optimization inverse problem vibration mode hyperelastic body finite deformation theory h1 gradient method |
| title | Shape optimization of a fish-like hyperelastic body vibrating with a swimming mode |
| title_full | Shape optimization of a fish-like hyperelastic body vibrating with a swimming mode |
| title_fullStr | Shape optimization of a fish-like hyperelastic body vibrating with a swimming mode |
| title_full_unstemmed | Shape optimization of a fish-like hyperelastic body vibrating with a swimming mode |
| title_short | Shape optimization of a fish-like hyperelastic body vibrating with a swimming mode |
| title_sort | shape optimization of a fish like hyperelastic body vibrating with a swimming mode |
| topic | shape optimization inverse problem vibration mode hyperelastic body finite deformation theory h1 gradient method |
| url | https://www.jstage.jst.go.jp/article/mej/9/1/9_21-00250/_pdf/-char/en |
| work_keys_str_mv | AT takuyahayashi shapeoptimizationofafishlikehyperelasticbodyvibratingwithaswimmingmode AT hideyukiazegami shapeoptimizationofafishlikehyperelasticbodyvibratingwithaswimmingmode |