著者

永井 拓生 沖 恵輔 長野 容平 木原 湧

出版者

一般社団法人 日本建築学会

雑誌

構造工学論文集B (ISSN:09108033)

巻号頁・発行日

vol.69B, pp.119-128, 2023 (Released:2023-04-07)

参考文献数

42

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The bending failure of full-culm bamboo is usually preceded by bending failure perpendicular to the fibers of the bamboo culm walls. Therefore, it is important to evaluate the stress perpendicular to the fiber that accompanies the bending of the bamboo culm. Brazier effect is considered one of the factors that cause this stress. In this paper, we discuss the bending failure mechanism and bending strength of round bamboo culms with formulation of the Brazier effect theory, numerical analysis, and experiments.According to the Brazier effect theory, when the bending moment for the bamboo culm is small, the bending stress perpendicular to the fiber is about 6 % of the stress parallel to the fiber. Also, the finite element analysis results and the Brazier effect theory showed good agreement in some conditions. The stress perpendicular to the fiber by numerical analysis lies between the linear approximation and the Brazier effect theory and is affected by the internode length. As a result of the bending experiment using Madake bamboo, the stress distribution in the part of the bamboo culm that is not directly subjected to the external force agrees well with the Brazier effect theory. However, it was observed that at the point where the concentrated load was applied, a large additional bending stress perpendicular to the fiber was generated in the culm wall, leading to bending failure of the bamboo culm.

著者

箕輪 健一 山口 力

出版者

一般社団法人 日本建築学会

雑誌

構造工学論文集B (ISSN:09108033)

巻号頁・発行日

vol.69B, pp.203-209, 2023 (Released:2023-04-07)

参考文献数

6

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The purpose of this paper is to verify the possibility of automatic deployment of an arch-shaped scissors truss by using shape memory alloy springs as actuators. For this purpose, we first conduct a construction experiment to confirm whether automatic deployment is possible by heating the shape memory alloy springs installed on the scissors truss by applying an electric current. In addition, since it is difficult to apply the proposed deployable structure without clarifying the specifications of the springs necessary for movement, the second purpose of this paper is to propose a method for determining whether automatic deployment is possible at the time of design. At that time, we try to evaluate whether automatic deployment is possible by focusing on the potential energy of the structure.

著者

福森 郁斗 西村 督

出版者

一般社団法人 日本建築学会

雑誌

構造工学論文集B (ISSN:09108033)

巻号頁・発行日

vol.69B, pp.190-202, 2023 (Released:2023-04-07)

参考文献数

22

被引用文献数

1

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In the biomechanics field, tensegrity structures are considered to be similar to the human skeleton and the joint. Oh proposed a biotensegrity model that mimics the human spine and presented a shape control strategy, which leads to the optimization problem with the lengths of the tensile members corresponding to the muscle and tendon as design variables. This study extends previous shape control methods by incorporating strategies to avoid obstacles. As the methodology, the potential method, which has been applied in robotic engineering, is adopted. This method derives an appropriate avoidance path from the potential field function.