著者

古巣 克也 尼子 龍幸 中川 稔章 浜辺 勉 青木 典久

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.858, pp.17-00326-17-00326, 2018 (Released:2018-02-25)

参考文献数

24

被引用文献数

1

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In this study, a formula describing on the flattening phenomenon when a bending moment acts on a box beam was derived considering the cross-sectional deformation. Calculation results obtained using the derived formula were then compared with results acquired using the finite element method (FEM). The case of a bending moment acting on a box beam composed of four thin plates that permits cross-sectional deformation along the longitudinal direction was investigated with the following assumptions: the boundaries of these plates is are simply supported, an equally distributed load acts on these plates, and the width along the neutral line of the plates is retained after deformation. Furthermore, on the basis of the coupling of the deflections of adjacent plates and the thin plate theory, the moment of inertia of cross section was obtained as a function of the curvature of the box beam. A formula relating the bending moment to the curvature is was then derived. Calculation results from this derived formula were compared with FEM results modeling only the cross section using generalized plane strain elements. For box beams with a square cross section, the maximum moments and curvatures calculated from the derived formula were within 5% of the FEM results. This indicates that it is important to consider the reduction in the cross section that accompanies the bending of the plates. Regarding general box beams with a rectangular cross section, the influence of the aspect ratio of the cross section was found to be considerably larger in the FEM results than in the derived formula. The reason for this difference may be that plates do not satisfy the abovementioned assumptions regarding the boundary and load conditions of the plates; however, confirming this remains a task for future work.

著者

古巣 克也 尼子 龍幸 中川 稔章 浜辺 勉 青木 典久

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集A編 (ISSN:18848338)

巻号頁・発行日

vol.79, no.801, pp.573-581, 2013 (Released:2013-05-25)

参考文献数

12

被引用文献数

2 8

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Recently, high strength steel material is used increasingly for plates which constitute the frame structures of vehicles. Since these plates become thinner, the buckling on the plates has been recognized as an important issue for automotive industries. In this paper, the expression is derived to obtain simply the shear stress on plates at torsional buckling for the box beams which represent the frame structure. Assuming the deflection shape of the buckled plate simply supported on all sides and the right angle at four corners, the precise expression is derived based on the energy method. However, this expression is complicated and hard to use easily. Therefore, the approximate expression is proposed by the knowledge from the aforementioned derivation. The accuracy of that expression is investigated as compared with the results acquired in the buckling eigenvalue analysis by FEM. As the results, the difference of shear stress at torsional buckling is less than about 5% as for the aspect ratio of the cross section between 0.4 - 1.0.

著者

鶴見 康昭 中川 稔章 西垣 英一 西脇 眞二 小島 芳生 菊地 昇

出版者

一般社団法人日本機械学会

雑誌

設計工学・システム部門講演会講演論文集 (ISSN:13480286)

巻号頁・発行日

vol.2001, no.11, pp.279-281, 2001-11-01

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An integrated system with both Computer Aided Design (CAD) and Computer Aided Engineering (CAE) has been developed. Most of these systems mainly focus on the effectiveness of constructing Finite Element (FE) model In these systems, a FE model is automatically constructed and calculation is automatically carried out. But a good design candidate cannot be obtained since some analysis tools for finding out it effectively are not included. In this paper, firstly some problems in current CAE systems are made clear. Secondly, in order to overcome these problems, two new analyses, that are FOA( First Order Analysis) in a concept design phase and a optimization tool based on a reduction technique in detailed design phase, are presented. Finally, in order to perform these analyses in a integrated system, a few concepts of necessary technique are proposed.