著者

山敷 拓也 羽賀 俊雄 熊井 真次 渡利 久規

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.804, pp.1156-1160, 2013 (Released:2013-08-25)

参考文献数

5

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A vertical type high speed twin roll caster is able to cast an aluminum alloy strip directly from a molten metal that is poured between the rotating rolls. However defects such as small cracks and unsound thickness distribution of the cast strip occur at faster roll speed. They are related to the contact condition of the roll surface and the melt. In the present study, we used the grooved roll to eliminate the defects, and to save the cost at the same time. We experimented using several grooved rolls with different patterns. When the groove width was 0.45mm; depth 0.2mm; pitch 0.1mm and 1.0mm, stable casting was possible. The shape of bulge was formed on the cast strip surface by the grooved roll. As a result of the color check, the grooved roll could eliminate the small cracks. The surface condition of the strip was more sound using the grooved roll with the pitch of 0.1mm than that of 1.0mm. Stopping the rotated roll during the casting, we observed the contact condition between the melt and the roll, and confirmed how the bulge was formed. To cold-roll for strip with bulges was possible and the bulges was erased. To cast for the sound strip was possible by the vertical type high speed twin roll caster with grooved rolls.

著者

山平 千治

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.42, no.265, pp.227-236, 1939-04-01 (Released:2017-06-21)

著者

山川 勝史 岩崎 遼一 細谷 直人 松野 謙一

出版者

一般社団法人 日本機械学会

雑誌

年次大会 2013 (ISSN:24242667)

巻号頁・発行日

pp._G051035-1-_G051035-4, 2013-09-08 (Released:2017-06-19)

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In this paper, numerical simulation for influenza infection was conducted using difference between air-flow course and virus-moving course. An alteration of radius of virus droplet changes sedimentation velocity. Then, the radius is affected by temperature and humidity around droplets. Flying virus drops may combine to other droplets. The repetition of the combination between droplets affects the sedimentation velocity of the droplet. Furthermore, using survival rate of influenza virus and human resistance, more realistic simulation is enabled. In this paper, the effectiveness of the method was shown carrying out infection simulation in an indoor environment.

著者

久米 智也 瀬名波 出 依田 欣文

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会九州支部講演論文集

巻号頁・発行日

vol.2019, 2019

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<p>The influence of photosynthesis on the growth of red algae <i>Agardhiella subulata</i> was investigated. First, changes in photosynthetic activity due to the amount of light irradiated on algae and changes in photosynthetic activity due to addition of CO₂ were tested under a total of 6 conditions including a seawater temperature of 25 °C, light intensity of 75, 150, 250 μmol/(m²·s) and CO₂ addition amount of 0, 15 mg/L. Next, the change in photosynthetic activity by seawater temperature was tested in total 3 conditions including CO₂ not added, light intensity of 150 μmol/(m²·s), seawater temperature of 20, 25, 30 °C. Measurement of the maximum quantum yield <i>F</i>v/<i>F</i>m, which is an indicator of photosynthetic activity, uses chlorophyll fluorescence measurement PAM. <i>F</i>v/<i>F</i>m with the continuous light period <i>L</i>24 h, CO₂ not added, the light intensity of 75 μmol/(m²·s) was the highest, and <i>F</i>v/<i>F</i>m decreased in a short time as the photon quantity increased. The maximum slope was 0.55 at sea water temperature of 25 °C and 30 °C, but the maximum value was 0.44 at 20 °C. In the continuous dark period <i>D</i> 24 h, <i>F</i>v/<i>F</i>m increased by about 0.10 at <i>D</i> 9 h regardless of the number of photons when CO₂ was not added and increased by about 0.10 at <i>D</i> 3 h at a CO₂ addition amount of 15 mg/L. <i>F</i>v/<i>F</i>m is an indicator of photosynthetic activity. It is thought that maintaining this high will lead to the growth of algae. Experimental results show that <i>F</i>v/<i>F</i>m is maintained high by setting the light period to 12 h and the dark period to 3 to 6 h. It was also shown that <i>F</i>v/<i>F</i>m is also affected by the photon quantity and CO₂. From the above it is considered that growth of seaweed can be expected by balancing the light period and the dark period.</p>

著者

中山 友裕 松田 昇一 棚原 靖

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会九州支部講演論文集

巻号頁・発行日

vol.2019, 2019

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<p>TIG welding is one of the welding methods widely used in industries for high reliability of joints, little occurrence of spattering and high convenience of construction. However, compared with other arc welding methods, there is a disadvantage that depth of penetration is sallow. To solve this problem, the authors propose a new ECMP (Electromagnetic Controlled Molten Pool Welding Process) method which controls the molten metal flow by using electromagnetic forces generated in the molten pool by a magnetic field perpendicular to the unidirectional current.</p><p>Incidentally, although the conventional ECMP method has mostly prevented the molten metal from sagging downward by using an upward electromagnetic force, the authors propose the use of a downward electromagnetic force in this study. When the direction of the magnetic field is reversed from the conventional method, in principle it is possible to obtain a downward electromagnetic force in the direction of gravity. Utilizing the downward electromagnetic force, improvement of the weld penetration in the TIG welding process of thick plates can be anticipated.</p><p>In this paper, the authors describe in detail their investigation of the influence of the generated downward electromagnetic force on the molten pool flow, the molten pool surface temperature, and the final bead shape when using the new ECMP method which forcefully uses such a downward electromagnetic force.</p>

著者

金澤 恵里 五十嵐 大貴 阿部 修 築地 徹浩 安永 和敏

出版者

一般社団法人 日本機械学会

雑誌

「運動と振動の制御」シンポジウム講演論文集 2013.13 (ISSN:24243000)

巻号頁・発行日

pp._C27-1_-_C27-10_, 2013-08-25 (Released:2017-06-19)

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Manifold blocks are recently used to connect hydraulic components in a hydraulic system that has flow channel inside. They are useful in reducing the size and weight of hydraulic systems. This paper deals with solid manifold block and laminated manifold block as trip equipment with which the turbine of a thermal power or a nuclear power plant is equipped. They are different from machining. We investigate pressure drops of their pipe flow with computational fluid dynamics (CFD) and compare the two types. We devised the new technique of having included CFD in pipeline network calculation. The final purpose is to design a laminated manifold block as trip equipment with which reduction in size and weight or reduction in pressure drops is realized. The conclusions from the aforementioned results are as follows. First, Branch/junction model can be calculated by the new technique of having included CFD in pipeline network calculation. Second, we achieved designing of a laminated manifold block as trip equipment with which reduction in size and weight or reduction in pressure drops is realized.

著者

篠原 主勲 奥田 洋司

出版者

一般社団法人 日本機械学会

雑誌

最適化シンポジウム講演論文集 2008.8 (ISSN:24243019)

巻号頁・発行日

pp.25-30, 2008-11-26 (Released:2017-06-19)

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To obtain the optimal shape of a 3D object minimizing the fluid traction, an adjoint variable method based on the variational principle is formulated and applied to the finite element method. The optimality condition of the present method consists of the state equations, the adjoint equations, and the sensitivity equations. In high Reynold's number cases, shape optimization methods are demanded that the initial shape be sufficiently close to the optimal shape and that Korman vortices not be present in the computational domain. Therefore, these methods were geneally applied to the steady state of the flows. In the present paper, the 3D adjoint variable method used to decrease the traction force of an object in unsteady flow is formulated by using FEM. The particularity of this method resides in the fact that both the start of the test time and the end of the test time in the optimization are determined by the stationary condition of the Lagrange function. The state variable is calculated from the start of the test time to the end of the test time in forward time and this data is saved, while the adjoint variable is calculated in backward time by using the saved data. The algorithm of the method is implemented using HEC-MW. By using the prepared algorithm, robust convergence of the cost function can be attained. This robustness makes possible the shape optimization even under unsteady flow containing Karman vortices.

著者

江口 透 山本 悠介 與田 光伸 村山 長

出版者

一般社団法人 日本機械学会

雑誌

生産システム部門講演会講演論文集 2013 (ISSN:24243108)

巻号頁・発行日

pp.31-32, 2013-03-11 (Released:2017-06-19)

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We have already proposed a job shop scheduling method to meet due-dates and to minimize overtime as far as possible. The sequence of operations of jobs is determined using the mixture of genetic algorithm and priority rule. In this report, we evaluate the performance of the proposed method by comparing it with lower bounds solved using a Lagrangian relaxation method. Numerical experiments show that the performance of the proposed method depends on the scale of problem and resolution time.

著者

田口 裕也

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.115, no.1121, pp.230-231, 2012-04-05 (Released:2017-06-21)

参考文献数

4

著者

劉 娟 堀江 三喜男

出版者

一般社団法人 日本機械学会

雑誌

機素潤滑設計部門講演会講演論文集 2010.10 (ISSN:24243051)

巻号頁・発行日

pp.171-172, 2010-04-18 (Released:2017-06-19)

被引用文献数

1

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The present study discusses the beauty of biped walking activity analyzing data points which are displacement, velocity, and acceleration of the waist, knee and ankle to time of a fashion model on a cat walk and the average adult man and woman's walking. Also, the differences in ankle displacement between a fashion model on a cat-walk, which is a beautiful biped walking activity, and the average adult man and woman's walking activity are discussed.

著者

川端 真澄

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.112, no.1093, pp.948-949, 2009-12-05 (Released:2017-06-21)

参考文献数

1

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

巻号頁・発行日

vol.86, no.881, pp.19-00256-19-00256, 2020

被引用文献数

1

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<p>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.</p>

著者

中川 智皓 森田 悠介 新谷 篤彦 伊藤 智博

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.82, no.838, pp.16-00052, 2016 (Released:2016-06-25)

参考文献数

11

被引用文献数

1

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In recent years, personal mobility vehicles (PMVs) have attracted huge attentions and widely developed. Compact PMVs can move through narrow spaces and they are expected to be used in pedestrian spaces. In this study, we aim to develop a four-wheel stand-up-type personal mobility vehicle for people who cannot walk far distantly because of the pain of foot or waist although they are able to walk for a short distance. The coupled model of human and vehicle is constructed by using multibody dynamics. In the model, the vehicle is expressed by one rigid body. The wheels, body, and handle are considered as a rigid body together. A human is expressed by 8 rigid bodies (foot, lower leg, femoral, body, head, upper arm, lower arm, and hand). The vehicle of the coupled model is accelerated in the numerical simulations. The behaviors of the center of gravity of a human with and without handle constraint are analyzed. As the result of the parametric study, it is found that the center of gravity movement is smaller when the value of the maximum acceleration and the acceleration time are small. It is also found that as the angle of the upper arm becomes large, the movement of the center of gravity is decreased.

著者

齋藤 款文 小林 稔彦 高島 俊

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集 2015 (ISSN:24243124)

巻号頁・発行日

pp._1A1-M09_1-_1A1-M09_4, 2015-05-17 (Released:2017-06-19)

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As one field of sports, there is a game of bike trial. Riders operate mountain bicycles with various advanced techniques. The purpose of this research is to create a bike trial robot that can operate a mountain bicycle and perform various maneuvers such as bike wheelie and etc. The bike-trial robot is able to clear level differences and ditches which other wheeled type robots cannot clear such obstacles and also cannot intrude into narrow spaces. Therefore, it is possible to use the bike-trial robot in the way of means of mobility for disaster sites. In this paper, in order to verify whether the robot can do Wheelie, it is studied that the robot model is created and simulated of wheelie in simulation soft. And, the prototype physical model of bike-trial robot for experiments is designed and constructed on a scale of two to five.

著者

武藤 大輔 高野 靖

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.746, pp.2495-2503, 2008-10-25 (Released:2011-03-04)

参考文献数

5

被引用文献数

3 3

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The dependence of transmission loss (TL) of a double-wall structure on the characteristics of the gases between the walls was investigated. The relationship between acoustic impedance, acoustic velocity, and TL was calculated by using the transfer matrix method. The results indicated that characteristics of the internal gases have two effects on TL. One is a change in the double-wall effect, and the other is a change in the reflection coefficient. Gases that have slower acoustic velocities or lower acoustic impedance than air increase the double-wall effect. Gases that have faster acoustic velocities increase the reflection coefficient. The calculated results for TL with air, helium, and carbon dioxide agreed well with experimental measurements. Finally, The rating of sound insulation (Rw) defined by JIS A1419-1 (ISO-717) was introduced, and the relationship between Rw and the characteristics of the gases between walls was investigated. The results indicate that gas with a low molecular weight and large ratio of specific heat is more effective to increase the TL.

著者

広瀬 通孝 石井 威望

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.51, no.471, pp.3153-3158, 1985-11-25 (Released:2008-02-21)

参考文献数

6

被引用文献数

3

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A quantitative method to analyze mental work, such as programming or CAD operation, is discussed. The authors are proposing to define an index, named 'RRV', which is a variance of interval between successive R-spikes in E.C.G.(Electro Cardio Graph). In order to increase the measurement efficiency of RRV and to extend the time range of the measurement, a simple and handy-sized measuring unit is developed. From the result of experiments, it is proved that RRV is strongly connected with the condition of mental work. Under such intensive mental work as repetitive calculation for a long time, the value of RRV of the worker becomes lower than that under usual mental work. In addition, other basic characters of RRV, for example, the time-scale of its dynamic behaviour, are studied. Lastly, as a practical application, RRV is measured during computer programming, and several interesting phenomena are observed.

著者

中島 晶 久保田 祥 佐々木 克彦 柳沢 祐介 岸 恭弘

出版者

一般社団法人 日本機械学会

雑誌

M&M材料力学カンファレンス

巻号頁・発行日

vol.2017, 2017

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<p>The subject of this paper is to calculate the residual stress occurred during heat treatments of the large forged steel using Finite Element Method (FEM). The analysis was carried out using a cylindrical FEM model of ASTM-A-470 used in rotor shafts for power stations. First, a heat transfer analysis was performed to obtain a temperature history, which is used to calculate material properties at varied temperatures. Then, using the temperature history, structure analyses were conducted considering both the creep deformation and the transformation plasticity. The residual stresses calculated by the structure analysis were compared with the value measured by experiments. As a result, the calculated residual stresses have the same tendency as the measured residual stresses when both the creep and transformation plasticity are considered. Therefore, the importance of both the creep and transformation plasticity for the structural analysis of the heat treatment of the large forged steels was confirmed. In addition, the effect of the cooling rate to the residual stress was also discussed.</p>

著者

角谷 治彦 瀬良 雅也 坂本 博夫

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 2018.28 (ISSN:24243078)

巻号頁・発行日

pp.1405, 2018 (Released:2019-05-25)

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Self-loosening of threaded fasteners sometimes occurs under dynamic loads such as vibration and shock. For mechanical structures, the self-loosening of threaded fasteners under transversely repeated load is particularly important. Although many parts for preventing the loosening of the bolt joints are evaluated the locking performance of selfloosening, there are not clear about the locking performance of the spring washer. The spring washers are used in many mechanical structures, so that in order to improve the reliability of the bolt joints, it is required to verify the effectiveness about the bolt loosening using the spring washer. In this paper, we clarified the effectiveness of the spring washer about the bolt loosening from the experimental evaluation of the bolt joints using the spring washer under the transverse vibration, and proposed the design guideline to adopt the spring washer based on the result. In the fastening using the spring washer, the lubrication state of the bearing surface and the mounting direction of the spring washer influence the self-loosening with rotation of the bolt joints under the transverse vibration. In order to prevent the self-loosening of the bolt joints using a spring washer, it is necessary to satisfy the condition that the fastening surface does not slip. And the spring washer functions effectively as the bolt tension compensation only when the residual bolt tension is smaller than the contact load of the spring washer.

著者

原 乙未生 荒井 文治

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.42, no.262, pp.38, 1939-01-01 (Released:2017-06-21)

著者

高橋 尚志 岩渕 功尚 斎藤 功

出版者

一般社団法人 日本機械学会

雑誌

公開研究会・講演会技術と社会の関連を巡って : 技術史から経営戦略まで : 講演論文集 2002 (ISSN:24329487)

巻号頁・発行日

pp.7-10, 2002-10-18 (Released:2017-06-19)