著者

西原 修 松久 寛

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.614, pp.3438-3445, 1997

被引用文献数

23

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Fixed points design methods for dynamic vibration absorbers are very well-known in the field of vibration control and commonly applied for practical absorber design. However, they must be understood to be approximation methods from the point of view of their design criterion that the resonance amplitude magnification factor is minimized. In this study, the exact algebraic expressions of optimum tuning and damping parameters for the minimization of the largest resonance amplitude magnification factor of linear dynamic vibration absorbers have been derived for undamped primary systems. The existence of two equal height resonance points is reduced to a multiple root condition of an algebraic equation. The determinant is handled as an equation with respect to the resonance amplitude. It has became very clear that the fixed points theory design by Brock is highly accurate. In particular, it exhibits very small error in the practical mass ratio range, e.g., below unity. Algebraic solutions also exist for the resonance frequencies and the anti-resonance frequency. A numerical extension of the method is introduced in order to investigate the optimization problem for damped primary systems.

著者

浅見 敏彦 細川 [ヨシ]延

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.61, no.583, pp.915-921, 1995

被引用文献数

6

---

This paper proposes an expression for design of optimal dynamic absorbers attached to damped linear systems. The classical expressions were derived from the assumption that the primary system has no damping. There are two optimization criteria in the design of the dynamic absorber : the fixed-points theory and the minimum variance criterion. In the fixed-points theory, the dynamic absorber is optimally tuned and damped with respect to the primary system so that the two resonant amplitudes of the main mass are equal. On the other hand, in the latter criterion the area under the power spectrum density curve of the main mass is adjusted to take the minimum value. The new expression proposed in this paper is based on the fixed-points theory. However, there are no fixed points in the resonance curves of the damped linear systems, so the analytic procedure becomes impossible. Therefore a perturbation method is used to obtain the expression, and the accuracy of the solution is discussed.

著者

森 みどり 中易 秀敏 三好 哲也

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C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.803, pp.2408-2423, 2013 (Released:2013-07-25)

参考文献数

21

被引用文献数

1 1

---

In order to keep a highly safe and reliable system of car driving, it is important that the system would be considered as a man-machine system including not only the feature of vehicle movement but also human perception, cognition, and motion of a driver. In this paper, it is examined to clarify the relation between feature of eye movements and driving behavior in conventional and unconventional situation by the experiments using the driving simulator and the eye tracking system. The measurements of time histories of eye movements were performed in the situation of different traffic regulation by the simulator. It is recognized in both turns that typical patterns of eye movements in horizontal axis appeared between the start and end of the turns. It is found from the time histories of eye movements by synchronizing that of vehicle data that the appearances of fixations were distributed uniformly on the trajectories of vehicle by trained drivers from the start of turning to the end, while the appearance of fixation by untrained drivers are concentrated in the beginning of turning or the end. These facts mean that the untrained driver did not receive visual information during the operation of turning, therefore the trajectories of vehicle by untrained driver showed the overshooting in the right turn and undershooting in the left turn.

著者

北山 哲士 山川 宏

出版者

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.67, no.653, pp.9-16, 2001-01-01

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金沢大学工学部

著者

倉迫 涼一 大日方 五郎 鳥谷 和史

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C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.800, pp.991-1002, 2013 (Released:2013-04-25)

参考文献数

13

被引用文献数

1 1

---

Lightening each part is needed as one method to improve the Fuel Economy of the car. On the other hand, a certain amount of mass is required for the brake rotor as thermal capacity because the main role of the brake is to convert the kinematic energy of the vehicle into the frictional thermal energy for decelerating the vehicle. Therefore, the appropriate heat design becomes important aiming at lightening brake parts. Many thermal analyses to design the strength and the cooling performance concerning the brake rotor are done. However, there are a few papers that treat the relation between the thermal analysis and the brake friction force. Authors have been developed the simple calculation method of the temperature on the friction surface where the pad and rotor come in contact. Then, it is found that contact form is one of factors in fluctuating brake friction force from the bench test data and the calculated friction surface temperature. In this paper, the calculation method of two dimensional temperature distribution of the rotor is proposed. The calculated results are effective to confirm the detail of radial temperature distribution of the rotor as a short time under braking. The tested pads and rotors were analyzed by EPMA on the friction surface. These results show that a detectable amount of tin is difference. It is found that the fluctuating brake friction force has affected by the relationship between the friction surface temperature and the melting point of tin.

著者

倉迫 涼一

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C編 (ISSN:18848354)

巻号頁・発行日

vol.78, no.786, pp.462-473, 2012 (Released:2012-02-25)

参考文献数

6

被引用文献数

2 1

---

Demands to vehicles performance from environmental view points are growing these days. Lightening each part is needed as one method to improve the Fuel Economy of the car. The main role of brakes is to transfer the kinematic energy of the vehicle to the dissipative thermal energy, and accordingly to lead the deceleration of the vehicle. On the other hand, a steady braking performance is important because it drives comfortably. The appropriate design of brakes for the stable performance requires the understanding of the temperature distribution based on the analysis of heat transfer. The friction force in a brake system is generated by making contact of the pad with the rotor. This study presumed that the friction force is depending upon the temperature of the surface where the pad and rotor come in contact. This study proposed a calculation method for estimating the temperature of the friction surface. Moreover, this study conducted the experiments to compare with the estimates from the proposed method. The experimental results agree with the estimations calculated from the proposed method. Based on the temperature distribution calculated by this method, considering how the shapes of the pad have an influence on the generated brake force.

著者

川島 進 渡邉 豊

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.77, no.778, pp.2376-2388, 2011 (Released:2011-06-25)

参考文献数

24

---

The center of gravity of a moving train differs time to time due to variety of number of passengers on board. There can be significant difference of 3D-locations of the center of gravity on the same train between at rush hour time and at off peak one. It is essential to detect the location for preventing rollover accidents of trains on which the critical speed of rollover for them depends. In this respect, this paper applies the innovative new theory of detecting 3D-locations of the center of gravity of a moving object for trains, which was invented by the second author of this paper and abbreviated as D3DCG(1). D3DCG was created by the concept of motion dynamics of a ship floating on water. This paper assumes that similar condition can occur while a train is moving straight at constant speed. Based on this assumption, the authors measured the vertical acceleration and the roll rate of moving trains, which were to be applied to D3DCG for trains, and were successfully able to detect 3D-locations of the center of gravity on trains by D3DCG.

著者

森山 淳

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.791, pp.2536-2548, 2012 (Released:2012-07-25)

参考文献数

10

被引用文献数

3 2

---

For the clarification of the overturning behavior of railway vehicle exposed to strong cross wind, several experiments were done to study the effect of wind velocity and wind direction on the wheel unloading ratio. In this paper, the results of the experiment at a line in the Kanto region are described. In this line, strong wind is often observed, and various types of train are operated. To get useful knowledge about the improvement of the critical wind speed of vehicle overturning, data were analyzed in terms of the vehicle cross-sectional shape. Results of the experiment show that vehicle specifications, such as a car weight, or a bogie suspension are little effective for overturning, if there are no difference about the cross-sectional shape. Analyzed results of the experiment also show that depending on the cross-sectional shape, the behavior of wheel unloading ratio by strong wind is different. These results suggest the possibility of the superiority of round shape roof for improving the performance against overturning.

著者

斉藤 俊 千葉 洋三

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.64, no.623, pp.2389-2394, 1998

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Two kinds of road racer bicycles are employed to research vibration characteristics of driving bicycles. After obtaing the natural frequencies and modes by vibration test in the non-driving state, practical driving tests are carried out. The acceleration of vibration in the middle of the handles and under the saddles are measured and the corresponding spectral density functions are calculated based on FFT method. The results show that in the driving bicycles, the dominant frequencies exist between 10 Hz and 50 Hz and the lower two modes in the non-driving state are excited.

著者

下田 昌利 山根 滉一

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C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.807, pp.4353-4367, 2013 (Released:2013-11-25)

参考文献数

21

---

This paper proposes a convenient numerical form-finding method for designing the minimal surface, or the equally tensioned surface, of membrane structures with specified arbitrary boundaries. Area minimization problems are formulated as a distributed-parameter shape optimization problem. The internal volume or the perimeter is added as a constraint according to the structure type such as a pneumatic or a suspension membrane. It is assumed that the membrane is varied in the normal and/or the tangential direction to the surface. The shape sensitivity function for each problem is derived using the material derivative method. The minimal surface is determined without shape parameterization by the free-form optimization method, a gradient method in a Hilbert space, where the shape is varied by the traction force in proportion to the sensitivity function under the Robin boundary condition. The calculated results show the effectiveness and practical utility of the proposed method for optimal form-finding of membrane structures.

著者

肥爪 彰夫 倉田 健二 中村 優一 松田 隆男

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.58, no.554, pp.2869-2876, 1992

被引用文献数

1

---

Excessively large transient torsional vibration is induced on the rotor system of modern large turbine-generators. This paper reveals that the coupling connecting the adjacent rotors acts as a hysteresis damper, and discusses the effect. First, a model is presented for the damping mechanism of typical shaft coupling. Second, the time-dependent nonlinear transient torsional vibration of the rotor system is investigated, using this model. Third, an improved coupling of higher damping capacity is introduced and investigated in the same way. Thus, the proper direction of the optimal design of coupling is clearly specified.

著者

呉 景龍 古谷 慎平 楊 家家 高橋 智

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.77, no.777, pp.2062-2070, 2011 (Released:2011-05-25)

参考文献数

10

被引用文献数

2 3

---

Driver safety is an important and often sensitive issue for seniors. Statistics show that the elderly are more likely than other drivers to receive traffic citations for failing to yield, turning improperly, and running red lights and stop signs all indications of decreased driving ability. Currently in Japan, half of the deceased in traffic accidents are elderly people. In present study, we focused on how the pedal placement affect on braking action in emergency. First, ten healthy young and ten elderly individuals were asked to perform a simple reaction experiment by foot. Then, the same subjects were instructed to complete a braking action experiment with different pedal placement condition. The results suggested that both simple reaction time and foot movement time of elderly subjects were significantly longer than that of young subjects. Moreover, the brake pedal force of elderly subjects was lower than that of young subjects. Thus, aging influenced both of simple reaction time and braking action in emergency. In addition, even the pedal placement changed characteristics of braking action of both young and elderly subjects, the most comfortable pedal placement of elderly subjects differed from young subjects.

著者

山本 普康 井上 剛 加藤 治 南田 勝宏

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.65, no.631, pp.1255-1260, 1999

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The surfaces of roll material were dulled by Nd-YAG laser machining under some conditions of focal length cooling and number of beams for laser irradiation, and the rolling and sliding wear experiments were made in order to investigate the wear resistance of crater rims formed on the dulled surfaces. Then, the effects of distances from a focusing lens to a roll material, cooling conditions of air and water and combined irradiation of 2 beams on the wear resistance of crater rims were clarified. As a result, it has been found that the condition of 1 beam irradiation, water cooling and appropriate focal length is the best for the wear resistance of crater rims in the present series of experimental conditions.

著者

井上 卓見 末岡 淳男

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.66, no.644, pp.1074-1081, 2000

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The authors present a new step-by-step integration scheme by utilizing the cardinal B-splines. The new method organizes conventional implicit methods such as Newmark-β method and Wilson-θ method and so on, and provides a simple computation procedure so that the step-by-step integration can be carried out efficiently. In addition, when we analyze a nonlinear system with discontinuity the computational acuuracy can be improved by the approximate detection of the points of discontinuity by making good use of the two-scale relation. In this paper, we formulate an algorithm of a time historical response analysis of a straight-line beam structure as an elementary example of multi-degree of freedom system besides a simple single degree of freedom system. The cardinal B-splines used here are only the ones of orders 3 and 4 but the other cardinal B-splines are also available for step-by-step integration in the same way.

著者

田辺 郁男 ジュニオール ライムンド ダ クルス イエー トット ソー 富岡 恭平 高橋 智

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.799, pp.748-758, 2013 (Released:2013-03-25)

参考文献数

16

被引用文献数

2 2

---

In the 21st century, as it is important to produce products with care for protecting the earth, a producer must be careful to conserve energy, save resources and reduce waste which pollutes environment. On the other hand, in case of a drilling, much cutting oil was also used for lubrication and cooling. This is large problem for protecting the earth. Therefore drilling technology using strong alkali water with micro-bubble was developed. A drill with through hole was used for this technology. Cooling effect of strong alkali water with micro-bubble was firstly investigated on the experiment. Then heat transfer coefficient of the drill with through hole was evaluted for cooling capacity. Tool life of the drill using strong alkali water with micro-bubble was also evaluated in the experiment of drilling using Ti6Al4V which has small thermal conductivity and is a material with difficult machining. It is concluded from the results that; (1) Cooling of strong alkali water with micro-bubble was very effectuive, (2) Heat transfer coefficient of the drill using strong alkali water with micro-bubble was 3.5 times of that of dry drilling, (3) Tool life of the drill using strong alkali water with micro-bubble was 6.5 times of that of dry drilling and 2 times of that of ordinary wet drilling respectively, (4) The drilling using strong alkali water with micro-bubble was economical and eco-friendly.

著者

川上 明 関森 秀伸 篠原 昭

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.59, no.566, pp.3224-3229, 1993

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In order to clarify the filament surface color for accident reconstruction, the experimental destruction of seven kinds of light bulbs was carried out by changing the time between the light bulb power off and bulb rupture. The following results were obtained. (1) According to the time, the oxidized color changes to dark grey, green, blue, purple, yellow, and light grey in this order. (2) The relationships among the time, color index number alloted to a typical filament surface color, and the light bulb's rated consumption of electricity were obtained as an approximate equation. (3) Elapsed time starting from the power off can be derived on the basis of the surface color or an approximate equation. (4) The oxidized color is very useful for traffic accident reconstruction. By means of this information along with conventional findings, drivers' behavior at the accident may be postulated more precisely.

著者

鈴木 悟史 中村 俊之 吉井 正広 中島 正勝 中西 洋喜 本田 瑛彦 小田 光茂

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.4233-4248, 2013 (Released:2013-11-25)

参考文献数

11

被引用文献数

1 1

---

Generally, many space satellites have large solar array panels for power generation and large antennas for observation and communication. The panels and antennas must be lightweight because of the payload weight limit of the launch vehicle. So, they are very flexible, with little damping ability. This results in vibrations cause serious problems. When the thermal environment around a flexible structure on orbit such as a solar array panel changes to cold or hot, the flexible structure produces its own deformation or vibration. These occur most often during rapid temperature changes called thermal snap or thermally-induced vibration, which has been known to cause attitude disturbance in Low Earth Orbit (LEO) satellites. Thermal snap vibration occurring on a flexible solar array panel is very slow. It is very difficult to measure thermal snap motion by sensors such as accelerometer. The behavior of a space structure affected by thermal snap has never been observed directly in space so far. This report presents the measurement results of “IBUKI” solar array panel's behavior using monitor camera.

著者

松島 和男 廣瀬 敏也 関根 道昭 谷口 哲夫

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:03875016)

巻号頁・発行日

vol.75, no.751, pp.535-537, 2009

参考文献数

1

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It is mandatory to apply a pressure relief device (PRD) on the Fuel cell vehicles to avoid explosion of high pressure hydrogen gas container when a vehicle explore to be on fire. Several hydrogen release tests were carried out to understand how the released hydrogen behaves in a vehicle fire. These tests are to analyze the release way of PRD as below. 1) The range of flame, flame temperature and the time of release when PRD effused hydrogen gas in upward direction, in downward direction, and in horizontal direction respectively. 2) The diffusion way of released hydrogen gas. 3) The effect of diffusion box which was assumed to decrease the hydrogen concentration and flow rate. The results showed that it should be avoided to release directly hydrogen gas into the air in the horizontal direction

著者

森島 圭祐 水内 淳 阿部 光一郎 古木 翔 山中 仁寛 大本 浩司

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C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.806, pp.3561-3573, 2013 (Released:2013-10-25)

参考文献数

31

被引用文献数

1 2

---

In this study, we conducted an experiment aimed at developing an effective method for measuring the useful field of view when driving while maintaining free visual (eye and head free) conditions with completely unobstructed head and eye movements. In the experiment, the mental workload was changed in a stepwise manner in order to test the hypothesis that the useful field of view becomes narrower as the mental workload (MWL) increases, as well as to verify the accuracy of the proposed method. The results confirmed the validity and accuracy of the proposed method for measuring the useful field of view under completely unobstructed visual conditions.

著者

野中 朋美 中野 冠

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.798, pp.408-417, 2013 (Released:2013-02-25)

参考文献数

24

被引用文献数

1

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This paper evaluates CO2 emissions generated during the manufacturing phase of global production network and discusses requirements analysis of green sustainable policies of global production network to prevent carbon leakage arising from transnational production. It calculates CO2 emissions from electricity used in manufacturing, emissions during transport from mining to manufacturing countries and emissions during transport from manufacturing countries to market. A case study of electric vehicle (EV) production includes outcomes calculated CO2 emissions in the manufacturing phase and transportation phase: for production in China, India, Thailand, Germany, Japan and Mexico to market in Japan, German and Singapore. It is illustrated that CO2 emissions during manufacture of EVs vary significantly, depending on the carbon intensity from electricity generation and each country's technical efficiency, and transport has a minor influence on emissions.