著者

射場 大輔 ロドリゲス・ロペス リカルド 神本 貴祐 中村 守正 三浦 奈々子 飯塚 高志 増田 新 森脇 一郎 曽根 彰

出版者

一般社団法人 日本機械学会

雑誌

北陸信越支部総会・講演会 講演論文集

巻号頁・発行日

vol.2016, pp._204-1_-_204-5_, 2016

被引用文献数

1

著者

大久保 博志 原田 恭輔 渡辺 大誠 佐藤 強 藤井 裕矩 丸山 勇祐 岩原 誠

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会関東支部総会講演会講演論文集

巻号頁・発行日

vol.2016, pp._OS0201-1_-_OS0201-2_, 2016

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A concept of a "Kite-type Wind-Power Generator" system is studied for evaluating the potential of an innovative high altitude wind power technology which utilizes a tethered buoyant WPG to extract energy from wind at higher altitude. The demonstration model consists of a straight blade windmill, a specially designed kite to elevate to high altitude, and a generator on ground, where the windmill and the generator are connected each other with a loop tether and wind energy is transferred from the windmill to the generator. A small demonstration model is studied experimentally by wind tunnel tests. Result of the present analysis and experimental study show an expecting facility to provide natural and eternal energy for the habitants in the city area.

著者

和田 訓佳 大竹 浩靖 小泉 安郎

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演論文集

巻号頁・発行日

vol.2002, pp.229-230, 2002

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The onset nucleate boiling and the point net vapor generation on subcooled flow boiling, focusing on liquid subcooling and liquid velocity were investigated experimentally and analytically. Experiments were conducted using a copper thin-film (35μm) and subcooled water in a range of the liquid velocity from 0.27 to 4.6m/s at 0.10MPa. The liquid subcoolings were 20,30 and 40K, respectively. Temperatures at the onset nucleate boiling obtained in the experiments increased with the liquid subcoolings and the liquid velocities. The increase in the temperature o* ONB was represented with the classical stability theory of preexisted nuclei. The measured results of the net vapor generation agreed well with the results of correlation by Saha and Zuber in the range of the present experiments. The temperature at the ONB decreased with increasing the size of surface roughness. The NVG was independent on the surface roughness.

著者

中村 海人 藤原 茂樹 Heil David 野中 誉子

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.2016, 2016

著者

藤原 茂樹 中村 海人 Heil David 野中 誉子

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.2017, 2017

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<p>In this paper, impression words of surfboards and surfing were obtained by interviewing to some pro surfers and armature surfers who have long time experiences. As mechanical properties of samples of center fins for a long board, weights and sizes of part were measured. Strain for bending tests were also measured as flexibility of the samples. A pro surfer and armature surfers who have rich and long experiences of surfing tested the samples with a same long board, but subjective evaluations were not fit the mechanical flexibilities.</p>

著者

山崎 光悦 伊藤 志成 恩田 佳明 平子 博

出版者

一般社団法人 日本機械学会

雑誌

北陸信越支部総会・講演会 講演論文集

巻号頁・発行日

vol.2003, pp.129-130, 2003

著者

吉田 達雄

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.102, no.964, pp.134-135, 1999-03-05 (Released:2017-06-21)

著者

フレディアント 梶山 拓也 吉田 準史

出版者

一般社団法人 日本機械学会

雑誌

Dynamics & Design Conference

巻号頁・発行日

vol.2019, 2019

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<p>Vibration reduction of vehicle is essential to improve the ride comfort. For evaluating the ride comfort, the vehicle vibration is occasionally analyzed in time domain. In this study, we propose a method to obtain the high contributing vehicle body vibration behavior deteriorating the ride comfort at a transient condition in time domain. We considered and applied two methods to realize the time domain analytical method. In the first method, we applied principal component (PC) analysis to the time domain vibration acceleration signals of the multiple body points at the transient condition to obtain the important vibration behavior. In the second method, we applied the PC analysis to the frequency domain signals and re-generated time domain signal by inverse FFT (IFFT). Through a simple vehicle vibration test at a transient condition and the comparison of the result, both methods were found to have ability to extract the high contributing body behavior at the transient condition but the second method utilizing IFFT was clarified to be more useful and accurate method.</p>

著者

井上 一博 フレディ アント 吉田 準史

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.2020, 2020

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<p>In this study, we considered a method to extract a hammering sound in noise environment by removing the noise component using noise transfer function for carrying out correct inspection of the target construction. In the first experiment, hammering test was performed using two tiles (defective and normal tiles) with or without loud white noise from a speaker. Through the proposed method using two microphones (single response and reference microphones), the hammering sound could be extracted well as the sound without noise. Subsequently, another hammering test was carried out when a drone was operated as an instance of the driving noise. However, the method using two microphones could not extract the hammering sound accurately. Then, the number of the reference microphone was increased from one to four to catch the generated noise of each rotating blade. As the result, the hammering sound difference between normal and defective tiles could be grasped better.</p>

著者

山崎 政彦 宮崎 康行

出版者

一般社団法人 日本機械学会

雑誌

スペース・エンジニアリング・コンファレンス講演論文集

巻号頁・発行日

vol.2013, pp._D01-1_-_D01-6_, 2013

被引用文献数

1

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平成25年度H-IIAによるALOS-2小型相乗り副衛星の一つとして,日本大学が提案している超小型衛星SPROUTが選定された.SPROUTでは,ソーラーセイルや大型太陽発電パネル等,将来の大型宇宙構造物の実現に向けて,インフレータブルチューブと膜面から成る複合膜面構造物の展開実証や膜面構造物による軌道降下率変化の予測等を行う.また,アマチュア衛星として,カメラ撮影やデジピータ利用等をアマチュア無線家に開放する予定である.本報告ではSPROUTの衛星・分離システム,複合膜面構造保持・展開システムの概要,開発状況について発表する.

著者

チルコティ ハリクリシュナ 菊川 豪太 小原 拓

出版者

一般社団法人 日本機械学会

雑誌

熱工学コンファレンス講演論文集

巻号頁・発行日

vol.2014, pp._B222-1_-_B222-2_, 2014

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In this paper, thermal conductivity of liquid n-alkanes in the vicinity of three crystal planes of a-quartz substrate terminated with H and OH-groups have been investigated using nonequilibrium molecular dynamics simulations. Methane and decane molecules are considered as alkane molecules in this study. It is found that the thermal conductivity fluctuates in an oscillating manner in the solid-liquid interface region. These fluctuations are typically in proportion to the oscillations in the density profile.

著者

浅井 勝彦

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C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.803, pp.2532-2545, 2013 (Released:2013-07-25)

参考文献数

10

被引用文献数

1

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In this research, I investigated the design of non-circular pulley for a force/torque profile adjustment mechanism. I proposed the generalized analytical design method of the non-circular pulley applicable to the majority of structures. By using this design method, the torque acting on the non-circular pulley and the force acting on the flexible part twisted around the non-circular pulley can be converted mutually to obtain a desired torque/force profile. Also I demonstrated the design of the non-circular pulley for a spring balancer and for an arm weight compensation mechanism. Furthermore, I investigated the design limit of the non-circular pulley, and showed that too long effective radius, too long offset length, and too short radius of curvature cause the problem of impractical non-circular pulley shape. From the analysis of the occurrence condition of each case, it became clear that the derivative of the effective radius is important for avoiding too long offset length and that the effective radius and the second derivative of that are important for avoiding too short radius of curvature.

著者

加部 隆史

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演資料集

巻号頁・発行日

vol.2009, pp.352-353, 2009

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労働安全衛生法第28条の2は,リスクアセスメントとリスク低減を求めている.通達によりこの実践方法をJIS規格を引用して示しているが,源則として国際機械安全規格の体系が示す隔離の原則・停止の原則・エネルギゼロの原則を示している.これは従来の労働安全による人への教育から,因果決定論の源としての機械の危険源を対処する方向転換である.危険な機械を囲い,動きを止めるという原理に基づいている為に機械の定常運転では有効だが起動停止を繰り返しユネイトな情報伝達が中断してしまう非定常時の作業での問題は必ずしも解決出来ない.技術を周囲環境取巻く周囲環境の多様化から,近年生産現場では人と機械の協働を可能とする要素技術が開発され,同時に一般消費者を対象としたサービスロボットが産業化に向けて準備されている.

著者

佐貫 亦男

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:00214728)

巻号頁・発行日

vol.82, no.727, pp.598-603, 1979

被引用文献数

1

著者

小川 竣 山田 崇恭

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.87, no.893, pp.20-00382, 2021 (Released:2021-01-25)

参考文献数

18

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In this study, we propose a topology optimization method for dynamic problems to control the deformation of the structure. To derive a structure that minimizes the deformation due to transient loads for an isotropic linear elastic model, the strain energy and the squared norm of dynamic compliance are set as objective functions. The topology optimization method applies a density method based on the RAMP method. In the case of the density method, since a optimal structure is obtained by an optimization algorithm based on the gradient method, it is necessary to formulate design sensitivity equations that can appropriately take into account the target optimization problem. A generalized sensitivity analysis method is proposed by introducing the adjoint method and applying Newmark’s β method, which considers the displacement as an unknown quantity , and considering the equations of motion. Furthermore, the accuracy of the sensitivity is verified by using the finite difference method as a benchmark, and it is shown that the proposed design sensitivity has high accuracy. Finally, as a numerical example, we derive optimal structures for several optimization problems and discuss the optimization problem settings to obtain a structure that can control vibrations. The validity of the proposed method is demonstrated by deriving the optimal structure to control the vibration.

著者

野田 雅貴 野口 悠暉 山田 崇恭

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.87, no.896, pp.20-00412, 2021 (Released:2021-04-25)

参考文献数

35

被引用文献数

1 4

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This paper provides a vector-valued level set-based topology optimization method for multiple materials. The proposed method is characterized by a perfectly symmetric representation of multi-material by a vector valued level set function, which lowers the dependence of initial configuration in the optimization calculation. The problem that the multi-material optimal configuration depends on how the parameters are given, due to the asymmetric material representation, is fundamentally solved. Also, this paper implements the method to adjust the geometrical complexity of optimal configurations with the regularization parameter. First, a topology optimization problem is formulated based on the representation by the perfectly symmetric vector-valued level set function, and the method to regularize the optimization problem is generalized for multi-material topology optimization. Next, we construct an optimization algorithm in which the level set function is updated by the reaction-diffusion equation. Finally, two- and three-dimensional numerical examples are shown to confirm the validity and utility of the proposed topology optimization method.

著者

新谷 浩平 畔上 秀幸 山田 崇恭

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.87, no.900, pp.21-00138, 2021 (Released:2021-08-25)

参考文献数

30

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This paper proposes a solution to a multi-material robust topology optimization problem of density type considering material uncertainties based on H1 gradient method. A material interpolation with respect to the density is introduced using the rational approximation of material properties (RAMP) and generalized it for the case with an arbitrary number of materials. Material uncertainty is considered by introducing random variables in the material interpolation scheme. The probability density functions of the random variables are assumed to be given. The topology optimization is formulated using the density which is given by a sigmoid function of the design variable. A weighted sum of the mean and standard deviation of the mean compliance is used as the objective function to control the tradeoff between optimality and robustness. To evaluate statistical moments of the objective function effectively, the univariate dimension reduction (UDR) and the Gauss-type quadrature sampling are introduced. A scheme to solve the robust topology optimization problem is presented using an iterative algorithm based on the H1 gradient method for reshaping. Examples of a two-dimensional cantilever beam under various material uncertainty exhibit the efficiency and flexibility of the approach. The accuracy of UDR is validated by comparing the results to the Monte Carlo approach.

著者

福留 功二 刺刀 一匡 大上 芳文

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 2014.89 (ISSN:24242756)

巻号頁・発行日

pp._9-3_, 2014-03-18 (Released:2017-06-19)

著者

水野 明哲 飯田 明由 福留 桂子

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演論文集 2004.2 (ISSN:24331325)

巻号頁・発行日

pp.145-146, 2004-09-04 (Released:2017-08-01)

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In order to improve the aerodynamic performance of vertical axis wind turbines (VAWT), effects of pitch angle of rotor blades were numerically investigated. To solve the complicated turbulent flow field around moving airfoils with small computers, discreet vortex methods were utilized. The numerical result shows that the pitch angle is important factor to improve the aerodynamic performance. In the case of pitch angle is 1 degree, an angle of attack becomes small at upwind position of the rotor blade, and therefore, flow separation is restrained at upwind part of the VAWT. As a result, the power coefficient is 10 % larger than that of the conventional (pitch angel is 0 degree) VAWT.

著者

青木 克巳 岡永 博夫 長瀬 二郎

出版者

一般社団法人 日本機械学会

雑誌

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集

巻号頁・発行日

vol.2013, pp._241-1_-_241-10_, 2013

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In this report, aerodynamic characteristic such as lift and drag of official rubber-balls used in the game of the baseball are studied experimentally. And the aerodynamic characteristic of these rubber-ball is compared and is examined with the aerodynamic characteristic of smooth sphere and sphere with dimple and the Major League ball. In addition, the aerodynamic characteristic for seam angle and spin rate ratio ratioα (=V/U, V: peripheral velocity of test balls, U: flow velocity)is also clarified. And, the flow pattern around the test balls are visualized by the spark tracing method. Following conclusions were got from these results. (1) The dimpled rubber-ball has a critical region where the drag coefficient decreases in the same way as the smooth surface balls. (2)Depending on the surface structure of test balls, the aerodynamic characteristics differ significantly. When dimples are added to the balls with seams, the critical region moves toward the lower Reynolds number side, but the minimum drag coefficient increases. (3)About the rubber-ball and Major League ball, C_D shows the almost same values without rotation. However at the rotational state, C_D of the Rubber-ball is lower than that of the Major League ball . (4)The values of C_D take different values depending on type A〜E and become large as α increases. The values of C_L stand in a same line which rises as α increase.