著者

白井 恭介 若松 栄史 森永 英二 久保 貴裕 堤 成一郎

出版者

一般社団法人 日本繊維機械学会

雑誌

Journal of Textile Engineering (ISSN:13468235)

巻号頁・発行日

vol.67, no.3, pp.41-56, 2021-06-15 (Released:2021-10-06)

参考文献数

11

被引用文献数

1

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A versatile method is proposed to predict the shape of a paper model of a three piece brassiere cup. A brassiere cup consists of several cloth and wire parts and the shapes of cloth parts called patterns are determined by repeating creation of a paper cup model, check of its 3D shape, and modification of 2D shapes of patterns. For efficient design of a brassiere cup, prediction of its 3D shape with a simulation is required. The deformed shape of a paper pattern is represented as a single or multiple developable surfaces. So, a model that can represent a pattern both as a single surface and as multiple surfaces is proposed. Which case is selected depends on the magnitude of the potential energy of the pattern in each case. The potential energy of the pattern and geometric constraints imposed on the pattern are formulated based on the model. Minimizing the potential energy under geometric constraints derives the stable shape of the pattern in either case. The validity of the proposed method was verified by comparing predicted and measured 3D shapes of paper models of two types of three piece cups.

著者

森永 英二 下村 幸弘 若松 栄史 荒井 栄司 中村 昌弘

出版者

一般社団法人 日本機械学会

雑誌

年次大会

巻号頁・発行日

vol.2018, 2018

著者

明石 一希 森永 英二 若松 栄史 倉橋 龍 荒井 栄司

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.83, no.853, pp.17-00084-17-00084, 2017 (Released:2017-09-25)

参考文献数

10

被引用文献数

2

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With recent globalization in industries, the number of failures and troubles of products caused by using them in unexpected ways has increased. In order to avoid such troubles, it is necessary not only to assume various ways of use thoroughly, but also to verify whether the design plan can fulfill required functions when the product is utilized in those ways. From this point of view, the authors proposed a functional verification method considering ways of use based on qualitative modeling of behavior of entities and cause-and-effect relationships among physical phenomena using Petri nets. It is, however, impossible to detect failures concerning to specification which requires dealing with quantitative information. This paper provides a method for quantitative modeling of behavior of entities and cause-and-effect relationships among physical phenomena. Two types of tokens were defined for dealing with positive and negative values and four types of arcs were for controlling changes of those values. These new elements of Petri net made it possible to represent behavior of entities and cause-and-effect relationships quantitatively. Application of this new modeling method to the functional detection method enables automatic detection of failures concerning to both functions and specification. The detection method using this modeling method was applied to an example, and its effectiveness was proven.

著者

小粥 雅貴 若松 栄史 森永 英二 荒井 栄司 島田 茂樹 眞鍋 賢

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.80, no.814, pp.TRANS0141-TRANS0141, 2014 (Released:2014-06-25)

参考文献数

12

被引用文献数

1

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In this paper, a prediction method of the maximum principal strain of a core/shielding wire contained in a coaxial cable, which is related to the life-cycle of the wire, is proposed. If the central axis of a wire is assumed to be twisted around a virtual cylindrical surface when a coaxial cable is straight and a virtual toroidal surface when the cable is bent, the shape of the wire can be described by the first and the second fundamental form of their surfaces in the differential geometry. The potential energy of the wire, which is bent, twisted, expanded, and/or contracted, is also formulated based on the differential geometry. Friction of the wire against the virtual surface is modeled as a virtual spring in the circumferential direction of the surface and its elastic energy is included in the total potential energy of the wire. Then, the stable shape of the wire can be computed by minimizing its total potential energy under geometric constraints. After that, the maximum principal strain is estimated from the shape of the wire. As a result of simulation, it was founded that a core wire is broken by bending fatigue before the shielding wire is if they have the same radius and rigidity.

著者

森安 竜大 若松 栄史 森永 英二 荒井 栄司 島田 茂樹 眞鍋 賢

出版者

一般社団法人 日本ロボット学会

雑誌

日本ロボット学会誌 (ISSN:02891824)

巻号頁・発行日

vol.30, no.8, pp.813-821, 2012 (Released:2012-11-15)

参考文献数

19

被引用文献数

1

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A modeling method to represent bending/torsional deformation of an electric wire is proposed based on the differential geometry. A twisted wire called a robot cable is used in a prismatic/rotational joint of an industrial robot to transmit signals or electric power. It is composed of a twisted bunch of several strands of many copper wires. The copper wire may be cracked by repeated bending/torsional deformation associated with the movement of a joint and such crack leads to wiring disconnection. To predict the life-cycle of the wires and to prevent such wiring disconnection, it is required to estimate deformation of not only the strands but also the copper wires when the wire is bent/twisted. In this paper, the deformed shape of a wire, which corresponds to a twisted bunch of n strands, is described by 3+2n independent variables and can be derived by minimizing the potential energy of each strand under various constraints. As the relationship between copper wires and their strand is similar with that between strands and their twisted bunch, the deformed shape of each copper wire can be also derived with the same method.