著者

橋本 直樹 薗部 正和 加藤 尚志 村上 徹

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

pp.19-00095, (Released:2019-09-05)

参考文献数

11

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JR east is developing a new ground coil to handle future speed increments in Shinkansen trains, as it is necessary to expand response distance of ground coils to cope with higher speeds. In addition, when lowering the mounting position of ground coils (as a measure against damage from falling ice), a need arises to adjust (expand) response distance. Therefore, in this research, we investigated measures to expand response distance of ground coils from the view point of feasibility, while maintaining compatibility with the current method. This research proved that an external power supply is effective for expanding response distance, so we have built a prototype ground coil with a built-in battery as a means of external power supply. The voltage detection control circuit supplies battery power only when electromagnetic waves are detected. The circuit configuration also uses a voltage induced by electromagnetic waves. This allows the battery to be used for more than 10 years. The high-speed rotation test confirmed that the prototype ground coil is capable of coping with 400 km/h even 300 mm from the ground coil and the on-board antenna. A falling-weight test confirmed that a new sturdier mounting base was capable of withstanding a load equivalent of 400 km/h. Since it was conformed that the prototype’s sufficient performance, we now plan to conduct a field test for practical use.

著者

宗像 鉄雄 永田 眞一

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.74, no.747, pp.2365-2371, 2008-11-25 (Released:2011-03-03)

参考文献数

6

被引用文献数

4 10

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Sodium acetate trihydrate is considered as the promising thermal energy storage material due to its high melting enthalpy at the melting temperature of 58°C. However, incongruent melting (phase separation) and remarkable supercooling are made difficult to use. In this study, solidification process of the sodium acetate trihydrate from supercooled state was both experimentally and numerically investigated. On the experiment, effects of supercooling and sodium acetate concentration on the crystal growth rate were measured by varying the supercooling temperature (-48K) and the sodium acetate concentration (40-55wt%) and obtained an empirical equation. Further, simplified crystal growth model, which is based on the experimentally obtained crystal growth rate, was also proposed and the heat release process, which is important for the thermal energy storage equipments, was investigated.

著者

永瀬 和彦 橋 弘矩

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.74, no.744, pp.1938-1947, 2008-08-25 (Released:2011-03-04)

参考文献数

26

被引用文献数

1 1

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The friction coefficient μ on the contact point position between a wheel flange and a rail is said to seriously affect on the occurrence of the wheel-climb derailment. However, the method to quantitatively and exactly evaluate the μ has not suggested until to the present. The authors proposed a method to easily and exactly evaluate the value, and made it clear by an experiment, employing a 1/5 scale model track and model truck. The result obtained through the experiment indicates that the value on dry rails has a similarity with that of the adhesion coefficient, and that the dry rail on the main line keeps the value at high level. Using the μ value obtained by the studies, the risk of the wheel-climb derailment was evaluated. As the result of the evaluation, they found that higher μ value than the conventionally used one should be introduced for the risk evaluation of the derailment, and that very short term lateral force below 60 ms should be observed on the steep curvatures.

著者

松井 信夫 江口 文夫

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:24242675)

巻号頁・発行日

vol.81, no.713, pp.325-329, 1978-04-05 (Released:2017-06-21)

著者

藤井 文夫 井上 吉弘 新田 高洋

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C編 (ISSN:18848354)

巻号頁・発行日

vol.78, no.788, pp.1133-1142, 2012 (Released:2012-04-25)

参考文献数

11

被引用文献数

3 6

---

Domino is a popular entertainment to enjoy the pleasing wave propagation in a row of solid pieces. This play game may be, however, a tough research subject of dynamic contact mechanics, because finite rotation, contact and friction are included in toy mechanics and these nonlinear effects are all of scientific interest. The major concern of this paper is to develop a computational model to study the domino wave propagation in a long straight row. More specifically, a total of N dominoes are modeled to rectangular rigid-body solids in shape of D (width) x H (height) x B (breadth). Equally spaced dominoes in a long straight row (L=492cm) are assumed to simply rotate around the front bottom edge. To trigger the wave propagation, the first domino is slowly inclined till its side diagonal slightly goes beyond the plumb line. The successive collision mechanism between individual toppling dominoes is investigated as a 2D problem in contact mechanics and we obtain an excellent agreement between the model prediction and experimental result.

著者

片桐 一彰 滝谷 俊夫 谷川 雅之 古寺 雅晴

出版者

一般社団法人 日本機械学会

雑誌

関西支部講演会講演論文集 2016.92 (ISSN:24242756)

巻号頁・発行日

pp.102, 2017 (Released:2017-06-19)

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Innovations in Technology of Aircrafts and their Development into Industry were studied. Firstly, the history of innovation on aircraft technology and industrial application was investigated. Secondly, the number of military aircraft and commercial aircraft manufactured after the 19th century were confirmed. Compared to the macroscopic economy of the United States, Western Europe and Japan, the effect of the aviation industry on the social richness was discussed. As a result, it became clear that the aviation industry has a high possibility of affecting the macroscopic economy of GDP since 1975 until today.

著者

水野 徳人 山川 勝史

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.845, pp.16-00049-16-00049, 2017 (Released:2017-01-25)

参考文献数

17

被引用文献数

1

---

Dolphin kick swimming is an underwater undulatory motion which is similar to the way dolphin and other cetaceans swim, and it's utilized after dives and turns in competitive swimming. Since in the international rules underwater limit is 15m which is 30% of 50m pool, this swimming technique has large effect on swimming records. Thus, it is essential to know and control fluid dynamics of dolphin kick swimming. In this paper, flow around human in dolphin kick swimming is simulated and the results are evaluated. To implement the simulation, dolphin kick movement is reproduced on computer by 3D model of male swimmer and changes of 5 joint angles are captured from the video footage, and the flow around swimmer model is computed by means of a moving grid finite volume method. This computational approach completely fulfills geometric conservation laws, so that moving boundary problems become resolvable. Also, a moving computational domain method actualizes unrestricted move of swimmer model. Furthermore, coupling of these methods and kinematics allows swimmer model to dynamically accelerate and decelerate by the forces applied to itself. The result shows that most of the thrust is produced in down-kick, and the ring vortex is generated in the wake, which appears in practical dolphin kick swimming. And the speed of swimmer model agrees with the speed of swimmer in the video footage.

著者

中嶋 大智 相田 健一郎 秋山 裕喜 瀧上 唯夫 富岡 隆弘 西山 幸夫 田中 隆之 宮本 岳史 今岡 憲彦

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.854, pp.17-00078, 2017 (Released:2017-10-25)

参考文献数

21

被引用文献数

3

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It is pointed out that the yaw dampers, which are often installed in between carbody and bogie frame of a high-speed railway vehicle, have such unfavorable points that the damping force is generated not only in the yawing direction but also in other direction. As a result the damping force is generated also to the longitudinal or pitching vibration of a bogie, and the excitation force acts in the longitudinal direction of the carbody resulting in the increase of the carbody vibration of the longitudinal or vertical direction. In this research, to enable the reduction of the excitation of the carbody vibration while maintaining the original function of yaw dampers to prevent bogie hunting motion, a new mounting structure of yaw dampers on railway vehicles has been developed. The new mounting structure enables to reduce the excitation force transmitted from a bogie frame to a carbody through yaw dampers. In this paper, the effect of yaw dampers on the carbody vertical vibration is firstly shown based on the results of an excitation test of a full-scale vehicle, then the outline of the new mounting structure for yaw dampers and the design and manufacture of the prototype device are presented. The vehicle dynamics model based on multi body dynamics was constructed and the suppression effect of the yaw damper force generated to movement in the direction other than the yawing direction of a bogie was verified by the numerical simulation. Moreover, the prototype device was installed on a full-scale test vehicle and a bogie hunting motion test was carried out to verify the running stability.

著者

藤川 正毅 石川 清貴 真壁 朝敏 田中 真人 笹川 崇 表 竜二

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

pp.15-00454, (Released:2016-01-15)

参考文献数

13

被引用文献数

6 5

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This paper proposes a novel implementation scheme of geometrically nonlinear finite element programs, which automatically compute exact internal force vectors and element stiffness matrices by numerically differentiating a strain energy function at each element. This method can significantly simplify the complex implementation procedure which is often observed in conventional finite element implementations, since it never requires B matrices, stress tensors, and elastic tensors by hand. The proposed method is based on a highly accurate numerical derivatives which use hyper-dual numbers and never suffer from any round-off and truncation errors. Several numerical examples are performed to demonstrate the effectiveness and robustness of the proposed method.

著者

太田 崇文 岡田 耕治 齊藤 梓 吉田 一也 村澤 剛 川上 勝 古川 英光

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.850, pp.16-00567, 2017 (Released:2017-06-25)

参考文献数

15

被引用文献数

2 4

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In this work, we present a comparison of the mechanical properties of 3D printed structures with respect to the printing orientation for 3D gel printer "SWIM-ER" and FDM (Fused Deposition Modeling) 3D printer with a result that the fracture surface of the 3D modeled object of the gel does not break along the stacked line, and the maximum stress at that time is the breaking strength. Also, the fracture surface of the 3D model of the ABS resin has broken along the stacked line other than 0 degrees, and the maximum stress at that time is the peel strength. The yield point can be observed at the 0 degree specimen, the maximum stress at that time is tensile strength. Moreover, while comparing both materials, we observed that the dependency in the stacking direction is weak in the 3D model of the gel, strong in the 3D modeled material of the ABS resin, and the dependence on the stacking direction is strongly influenced by the way of bonding the materials in stacking.

著者

廣瀬 徳晃 津坂 祐司 清水 毅 山内 智裕 白石 孝 谷中 壯弘

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.81, no.826, pp.15-00087, 2015 (Released:2015-06-25)

参考文献数

17

被引用文献数

2 5

---

The various kinds of the electric personal mobility, which is one or two-seater, are being developed all over the world. These mobilities are applied into the substantiative experiment held in the several cities in order to investigate the effectiveness and popularity. The main specification of the personal mobility is the small footprint to reduce the parking space and alleviate traffic jam. However, the small footprint causes the deterioration of the posture stabilization. The authors are developing the personal mobility, which has a lean actuator to tilt the upper body for keeping the posture stabilization not only during turning motion but also on the uneven road surface. In this paper, the motion model considering yaw motion around roll axis is derived. In addition, the posture control method based on the motion model is proposed to realize the desired roll angle, which ensures the required range of the zero moment point. The effectiveness of the proposed approach is verified by the experiments using a prototype.

著者

多賀 祐重

出版者

一般社団法人 日本機械学会

雑誌

機械學會誌 (ISSN:24331546)

巻号頁・発行日

vol.31, no.134, pp.234-257, 1928-06-20 (Released:2017-08-01)

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The pacific type passenger locometive (type 18900) has been a typical one of locomotives for express trains on the main lines of Japanese Government Railways. In order to meet the requirement for larger tractive power of locomotive, as a result of the introduction or steel cars, causing the increased weight of the train, the three cylinder pacific type locomotive (type C53) has been newly designed, constructed and put in the above mentioned service. In this paper, the writer treats the characteristics and special features in the construction of this new type locomotive.

著者

濱野 拓人 小野里 雅彦 田中 文基

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.859, pp.17-00480, 2018 (Released:2018-03-25)

参考文献数

19

---

House-collapsing simulation using a physics engine is an effective method for acquiring structural data regarding collapsed houses with the aim of understanding the properties of destroyed or disordered structures for designing and operating rescue-robots. However, the simulation needs a lot of time since a house model consists of a large number of rigid bodies and joints. In order to find an appropriate configuration of computer hardware and software for accelerating house-collapsing simulations, this study evaluates the performances of four major physics engines, namely Open Dynamics Engine, Bullet Physics Library, PhysX 2.8.1 and PhysX 3.4, by comparing the processing time about two sample structures including only rigid bodies or rigid bodies constrained by joints. Results of the experiments show that the use of multi-core CPU and GPU, especially high-speed GPU, on PhysX 3.4 has the best performance since it can process a large number of rigid bodies and joints in parallel. Based on the results, an existing simulation system has been improved and the collapsing process of one-house, which consists of about 7,500 rigid bodies and 15,000 joints, can be simulated in real-time using multi-core CPU and GPU. Moreover, this study estimates the size of GPU memory which is required for simulating the large-scale field on PhysX 3.4 to enlarge the scale of simulation. Consequently, the collapsing process of thirty-houses which includes interactions between collapsed houses can be simulated.

著者

小野 京右 武川 浩士

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.63, no.608, pp.1110-1117, 1997 (Released:2014-03-12)

参考文献数

5

---

A mathematical method of complex modal analysis and an experimental identification procedure of modal parameters for nonproportionally damped mechanical systems have been established thus far. However, the physical structure of complex modes of nonproportionally damped systems has not been thoroughly understood. This paper deals with a physical and graphical interpretation of complex modes in comparison with real modes of proportionally damped systems using the complex plane and the complex vector space. It is explained why the resonance vibration of nonproportional-ly damped systems does not exhibit the natural mode shape which appears in the free vibration of the same system. The condition that makes the resonance vibration mode approximately coincide with the natural mode shape of the free vibration is discussed.

著者

村瀬 晃平 ZHU JING 松本 健郎

出版者

一般社団法人 日本機械学会

雑誌

バイオエンジニアリング講演会講演論文集 2017.29 (ISSN:24242829)

巻号頁・発行日

pp.2D17, 2017 (Released:2017-06-19)

著者

高田 宗一朗

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.86, no.881, pp.19-00172, 2020 (Released:2020-01-25)

参考文献数

13

被引用文献数

1

---

The author proposed the identification method of symmetric nonlinear system based on the Auto-Regressive analysis and the method of averaging in a previous paper. However, there is a problem that conventional methods including the one in the previous paper cannot address the identification of asymmetric vibrating systems. In this paper, the system identification in asymmetric nonlinear system is investigated. At first, formulation of identification problem is conducted. The identification problem is described using the method of Krilov-Bogoliubov-Metropolsky is considered the two-order approximation. The description contains the amplitude dependency however coefficient of the sign cannot discriminate. Therefore, this paper proposes a new system identification method to solve these problems by identifying appropriate sign of nonlinear parameters based on movement of center-of-vibration. Identification experiment is conducted using numerical investigation, Runge-Kutta method. A nonlinear coefficient is considered in two cases: positive number and negative number. In both cases, the proposed method gives good estimated results which show good agreement with the true values. Moreover, identification experiment is conducted using the cantilever system subjected to the magnetic force. The proposed method gives estimated results which shows good agreement with the true experiment values.

著者

佐藤 俊之 永瀬 純也 嵯峨 宣彦 齋藤 直樹

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.17-00142, 2017 (Released:2017-09-25)

参考文献数

24

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This paper proposes a two-degree-of-freedom control systems design using a preview feedforward controller called zero phase error tracking controller (ZPETC) to improvethe tracking performanceof the disturbance observer-basedPredictive Functional Control (PFC) systems. To this end, we derive a pulse transfer function representation of the PFC controller, which is used for the design of ZPETC, and show some properties of the PFC controller. Then a disturbance observer-based PFC system combined with ZPETC is designed. Several experiments using a single axis table drive system are conducted to validate the effectiveness of the proposed control method. The experimental results show that the tracking error is dramatically reduced compared to the previously-developeddisturbance observer-based PFC.

著者

藤川 正毅 田中 真人 井元 佑介 三目 直登 浦本 武雄 山中 脩也

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.86, no.881, pp.19-00256, 2020 (Released:2020-01-25)

参考文献数

20

被引用文献数

1

---

A numerical calculation scheme for stress and its consistent tangent moduli with hyper-dual numbers(HDN) for Ogden-type hyperelastic material model was proposed. The main advantage of this scheme is that once the framework is coded, any Ogden-type hyperelastic material model can be implemented by only re-coding the strain energy density function. In this scheme, the new differentiation method for eigenvalue and eigenvector of the symmetric matrices with HDN were proposed. The proposed method can calculate the eigenvalue and eigenvector in non-real part analytically by using the eigenvalue and eigenvector in real part, in case that all eigenvalues in real part are not multiple root. We implemented the Neo-Hookean model and the Ogden model with the proposed scheme, to confirm the effectiveness and robustness of this method, and applied it to some examples. As the results, it was confirmed that the numerical results of the proposed method showed good agreement with analytical ones.

著者

松岡 清利

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.43, no.376, pp.4501-4509, 1977-12-25 (Released:2008-03-28)

参考文献数

8

被引用文献数

2 3

著者

下田 昌利 近藤 晃 劉 陽

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C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.807, pp.4014-4027, 2013 (Released:2013-11-25)

参考文献数

21

被引用文献数

2

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This paper presents an optimum design method considering structural performances and Kansei, which has been becoming an important issue for product designs with maturation of consumer demands. The response surface methodology combined with the design of experiment technique is applied to a bicycle frame design problem. The strength and the rigidity calculated by FEM are used as the evaluation functions for the structural performances. Three dimensional rendering models are constructed with computer graphics software, and used for the Kansei evaluation. The Kansei performances such as “individual” and “elegant” are evaluated by the Semantic Differentials technique and quantified. A road-bicycle frame is focused on as an application example of this method. Sizes of the cross section at both ends, position and angle of rotation at the midpoint of each frame are defined as the design variables to be optimized. By using the response surfaces between the design variables and the performances, the form of road-bicycle frame is optimized under various objectives and constraints. The form with the optimized design variables is visualized with the CG software.