著者

高橋 由紀夫 戸村 典章

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.78, no.790, pp.799-803, 2012 (Released:2012-06-25)

参考文献数

7

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Japan Society of Mechanical Engineers has developed various guidelines in relation to structural integrity of nuclear and fossil power plants. The guideline for evaluating modes and consequences of potential failure in particular part of piping system in nuclear power plants is one of them. Main part of this procedure is dedicated to the evaluation of likelihood of leak-before-break behavior and evaluation of leak rate. Leak-before-break evaluation requires prediction of fatigue crack growth from a prescribed initial flaw until penetration, calculation of crack length providing detectable leak as well as that causing unstable fracture. Specific guidance is given for each part. This paper discusses the scope and the outline of the present guideline.

著者

佐藤 慧拓 窪田 佳寛 望月 修

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.833, pp.15-00386, 2016 (Released:2016-01-25)

参考文献数

11

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Many features of organisms have the possibility that can be applied to the infrastructure and network system for the communication. From the previous studies, the network system of the venation is known as the strong network on the damage. This relates the structure of leaf vein. In this study, we are focusing on the network of leaf vein to understand the strong network system. First, we study the network structure to know the relation between damage on leaf and the strong network. Then, the influence of damage on leaf vein for the water absorption on the leaf was studied with the dye flow visualization. The result shows that the network type of vein on real leaf is the mesh type network. The mesh type network has the benefit to make a bypath when the vein has the damage. The result of dye flow visualization shows that the real leaf requires the single vein to make a bypath for damage region. The increasing of area on water absorbed relates the distance of water absorption. This means that number of vein is not dominant for the speed of water absorption. Therefore, the network of leaf vein has a high robustness from the damage of vein by the mesh type network.

著者

樫山 武士

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.113, no.1096, pp.158-159, 2010

参考文献数

2

著者

篠田 軍治 長田 重昭

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.8, no.32-1, pp.117-120, 1942-09-25 (Released:2008-03-28)

著者

小出 貴宏 熊谷 直紀 佐藤 健輔 田村 宏司 河原 健太郎 播磨 賢司 福島 忠徳 橋本 英一 杉木 光輝 竹ヶ原 春貴

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 2003.11 (ISSN:24243191)

巻号頁・発行日

pp.15-20, 2003-01-23 (Released:2017-06-19)

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Pulsed Plasma Thrusters (PPT) using Teflon as solid propellant has characteristics of simplicity, lightweight, and high durability in recent years. Therefore, PPT propulsion system has the advantages for the small, micro-and nano-satellite attitude control. Tokyo Metropolitan Institute of Technology (TMIT) has started R & D on PPT system with the collaboration of NASDA. This paper describes its present status of the R & D. In the BBM phase, we tested that hood angle and electrode material was changed. In this result, we have researched optimum performance of TMIT-PPT. Now we have shifted from BBM-phase to EM-phase.

著者

西本 哲也 村上 成之 阿部 俊昭 小野 古志郎

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:03875008)

巻号頁・発行日

vol.61, no.591, pp.2386-2392, 1995-11-25 (Released:2008-02-21)

参考文献数

16

被引用文献数

7 6

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The purpose of this study is to understand the mechanical properties of the human cranium in order to develop a FEM simulation model of the head. Craniectomy samples, autoclave bone flaps and dry cadaver skulls were tested using values of radial bending moment considered typical in the case of head injury. In this study, we developed a procedure for estimation of the mechanical properties of the cranium by assuming a proportional relation between the bone mineral density and Young's modulus. The mechanical properties of the human cranium have been determined from the three-point bending test and the bone mineral density measured by the dual energy X-ray absorptiometry. The human cranium consisted of inner and outer tables (cortical bones) and a diploe (a cancellous bone). The stress on the cortical and the cancellous bones in the field of bending stress was assumed that the cranium was a beam in which two different materials were combined. The experiment showed that fresh cranial fractures start at the inner table and the diploe and then propagate to the outer table. The fracture of a cranium taken out of a human being will exhibit elastic-plastic fractures. This fact implies that the inner table and the diploe fractures can occur even if no fracture is detected using plain X-rays in cases of acute extradural hematomas (EDH).

著者

竹腰 久仁雄 後藤 學

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.70, no.695, pp.2155-2162, 2004-07-25 (Released:2011-03-04)

参考文献数

12

被引用文献数

2 3

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It has long been believed that the tip of a knife-edge has a single small radius and the radius becomes larger with abrasion during daily use. Recently, for the most popular knife made of SUS 420J2, the authors have found that the tip has two micro-blades (the secondary blades) with a groove between them along the knife-edge and the groove grows and thus its width becomes larger with cutting operations. In this paper, this evidence is confirmed to be true even for the knife of a heat resisting alloy-SUH3 and a high-hardness Zirconia Ceramics, and thus it is concluded that the formation of such groove and its growth is a general phenomenon for almost all knife-edges. For each tested blade, the relationship between the cut piece number of paper (NCP ; the cutting performance) and the repetition number of abrading operation (Nt) is approximately expressed as an exponential relation. Ideas to express the durability of cutting performance (Nt*), the total cutting performance (TNP) and the feeling of cutting paper (ACP) through the service period are proposed and quantitatively evaluated for the tested materials. It is surprisingly found that even for the brittle Ceramics, the relationship between the groove spread and Nt is almost the same as those for SUS420J2 and SUH3. In comparison with SUH3 and SUS420J2, Zirconia Ceramics has the highest durability Nt*, the best total cutting performance (TNP) and the best feeling of cutting (ACP). The ratio of the durability, total performance and the feeling of cutting to those of SUS420J2 are 28, 40 and 1.4 for SUH3, and 48, 71 and 1.5 for Zirconia Ceramics, respectively.

著者

田井 英二

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.100, no.942, pp.566, 1997-05-05 (Released:2017-06-21)

著者

猪谷 一郎

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.70, no.586, pp.1690-1694, 1967-11-05 (Released:2017-06-21)

被引用文献数

1

著者

大瀬戸 篤司 近野 敦 増子 弘二 小泉 卓也 内山 勝

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 2012 (ISSN:24243124)

巻号頁・発行日

pp._2A1-H10_1-_2A1-H10_4, 2012-05-27 (Released:2017-06-19)

被引用文献数

1 1

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Quad rotor helicopters has simple mechanism and high stability. However, it is not easy for a quad rotor helicopter to fly long time and long distance, because most of the thrust is consumed to lift the body, and hence horizontal component of the thrust is small. In this paper, we present the experimental results of a quad rotor tail-sitter UAV (Unmanned Aerial Vehicle) which is composed of a quad rotors and fixed wing. Developed UAV can hover like a quad rotor helicopter, and can fly long distance like a fixed wing airplane. We designe attitude and altitude control system of the UAV for hovering. In order to verify the designed control systems, we conducted hovering control flight experiment. Additionally, we identified both the impact of propeller slipstream on yaw control and the solutions.

著者

石崎 啓太 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 (ISSN:21879761)

巻号頁・発行日

pp.18-00050, (Released:2018-10-02)

参考文献数

55

被引用文献数

3

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This study systematically analyzed life cycle CO2 (LCCO2) emissions of a comprehensive set of mass-produced 2,000 cc class sedan-type vehicles, using a hybrid life cycle inventory approach. Gasoline and diesel internal combustion engine vehicles (ICEVs), hybrid electric vehicle (HEV) as well as battery electric vehicle (BEV) and fuel cell vehicle (FCV) were investigated, considering (i) the current BEV market trends, (ii) Japan's energy mix (the average for 2012–2014), and (iii) the use of the HVAC system. The results show that the annual average increment of CO2 emissions in use phase by HVAC system in Japan (assumed annual mean temperature of 15°C) was presumed to be evenly 9% regardless of vehicle types, although further detail analysis is required. The CO2 emissions in use phase of BEV were higher than those of HEV and FCV (applied hydrogen produced by steam reforming of LPG (on-site)) due to thermal power dominant electricity generation mix in Japan in recent years. As a consequence of high CO2 emissions from power supply and battery production, the LCCO2 emissions of BEV equipped with 75 kWh battery were higher than those of HEV, FCV (on-site), and conventional ICEV (diesel). By reducing the battery capacity to 40 kWh or less, the LCCO2 emissions of BEV become lower than those of ICEVs and FCV (on-site), making BEV a competitive alternative. However, it is difficult that BEV mitigates both LCCO2 emissions and driver's range anxiety. In conclusion, HEV shows the competitive performance in terms of LCCO2 emissions with long driving range in Japan.

著者

佐藤 理 岩井 裕 吉田 英生

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.85, no.871, pp.18-00365, 2019 (Released:2019-03-25)

参考文献数

18

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The purpose of this study is to develop an analytical model of cross-flow heat exchangers with offset strip fins which are usually equipped in the aircraft air conditioning system (so called the environmental control system, ECS). The ECS mainly consists of four cross-flow heat exchanges, i.e., a primary heat exchanger, a secondary heat exchanger, a reheater and a condenser. Because of the special requirements of the design for the aircraft, the primary and secondary heat exchangers are set adjoiningly; the reheater and the condenser are also set adjoingly. Therefore, in both the pairs, the effect of the temperature profile of the upstream component (the secondary heat exchanger or the reheater) on those of the downstream component (the primary heat exchanger or the condenser) should be taken into account for precise prediction of the system. To this end, a core element model was newly proposed in this study. In addition to the effect of temperature profile, phase changes (condensation and evaporation) of water included in the humid air simultaneously occur except for the primary heat exchanger. Regarding these phenomena, the method of sensible heat fraction (SHF) to convert the latent heat into the equivalent sensible heat was introduced, and the global and local SHF models were examined by comparison with the experiments. The prediction by these models were found to agree well with the actual performance of the ECS operations.

著者

井上 剛志 高木 賢太郎 竹崎 勇輝 石川 昌義

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.789, pp.1680-1690, 2012 (Released:2012-05-25)

参考文献数

7

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The gyroscopic exercise tool which utilizes the gyroscopic effect caused by the whirling motion of the high speed rotating body to train the hand muscle is considered. This tool utilizes the contact phenomenon between the rotor and the case. When the input motion with 3-5 Hz is added to the case, the rotor spins in thousands rpm whirling with the precession motion which is synchronous to the input case motion. Conventional studies on this tool have assumed the continuous rolling motion of the rotor to the case. This paper does not set this assumption, and investigates the dynamical modeling of this tool considering the contact/non-contact conditions and the slip between the rotor and the case. Two kinds of motions are observed in the numerical simulation, one is the uniform precession which was observed in the conventional studies and the other is the periodically reverse precession. These two motions are physically explained, and are also observed in the experiment.

著者

長谷川 雄太 青木 尊之 小林 宏充 白﨑 啓太

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.18-00441, (Released:2019-02-07)

参考文献数

18

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We implement and perform large-scale LES analysis for running groups of cyclists. The mesh-refined lattice Boltzmann method (LBM) and coherent-structure Smagorinsky model (CSM) are adopted for the simulations to achieve a high performance computing on the recent GPU supercomputer. In the simulation with 16 cyclists, the mesh spacing around cyclists is 4 mm, and the total number of the mesh is up to 8.1×108 and the number of GPUs utilized is up to 64. Each calculation took 4 or 5 days for the 8~11 seconds of physical duration. The flow around 16 cyclists in various arrangement is calculated, and the results show that the in-line arrangement is more effective than the rhomboid arrangement in the viewpoint of the total aerodynamic drag of the group; however, a specific person in rhomboid arrangement can obtain larger drag reduction and save the endurance. Results on two groups also suggest that the frontal group in rhomboid arrangement will be exploited as the wind protection of the backward groups.

著者

梅田 綾子 清水 悦郎 南 健悟 三好 登志行

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.860, pp.17-00464, 2018 (Released:2018-04-25)

参考文献数

20

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In recent years, engineering technology has become essential for our daily life. We cannot live without civil engineering or information technology even for one day. At the same time, as utilizing technologies sometimes infringe human rights, many laws and regulations exist in our society. In spite of importance to collaborate with legal experts for engineer to realize implementation of their new technologies into society, and a lot of efforts of the Professional Committee of Law and Technology in the Japan Society of Mechanical Engineers, it has not been understood in Japan for a long time. Many issues have been discussed relating to the growing concern about autonomous vehicles, but it seems insufficient from the view of legal and engineering collaboration. In this paper, a case study is introduced that is an example of legal engineering showing countermeasures for legal issues to realize autonomous shipping performed by Robotics Laboratory in Tokyo University of Marine Science and Technology. Furthermore, knowledge obtained by this case study is proposed as legal engineering which presents how engineers may identify legal issues and perform risk assessment of their developing technologies. By communicating with legal experts, engineers might be able to perform technology development with legal risk mitigation and take a role for rulemaking especially in the field of soft-law.

著者

熊谷 正芳 石渡 正人 大谷 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 (ISSN:21879761)

巻号頁・発行日

vol.84, no.863, pp.18-00139, 2018 (Released:2018-07-25)

参考文献数

18

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Residual stress measurements on pipe-shaped Ni-alloy, Inconel 625, were conducted. The pipes were made from a thin plate by roll-bend and weld along longitudinal direction of the pipe. Shot peening processes were performed to the outside surface of the pipes. The stresses were measured using X-ray stress measurement method. The residual stresses on the specimen before shot peening process were around 100 MPa toward longitudinal direction and around 250 MPa toward transvers direction to the welding direction. The residual stresses changed to 800 MPa in compressive by shot peening process. After thermal aging at 1173 K for 1 and 10 hour, the residual stresses changed to −100 MPa on the specimens with and without shot peening in both longitudinal and transvers directions. In addition, optical microscopic observation and the analyses of X-ray diffraction peaks were performed to reveal microstructural features due to welding, shot peening, and thermal aging. Equiaxed and columnar dendrites were generated in the center and the outer of fusion zone, respectively. The grains in the heat affected zone, between the fusion zone and base metal became larger. The grains near the surface even in welds became small by shot peening processes according to analyses of X-ray diffraction peaks. Even though induced compressive residual stresses were released during thermal ageing, refined grains had been smaller than before shot peening process.

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.782, pp.3808-3817, 2011 (Released:2011-10-25)

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オーサーシップの問題により,論文の撤回,削除が妥当であるとの決定がなされたため.

著者

黒木 康平 溝田 武人 大屋 裕二 岡島 厚

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.2008, pp.147-148, 2008

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Less spinning soccer ball aerodynamics are studied by wind tunnel experiments. Aerodynamic force of unsteady lift and side ones acting on the ball at rest are measured and estimated flight trajectory. Well agreements of flight shift magnitude in lateral direction between observed and calculated ones are obtained. As a result, in this stage the cause of this strange behavior of less spinning soccer ball is clarified by self-excited buffeting phenomenon of irregular behavior of horseshoe-shaped vortex and longitudinal twin one, which already discovered with supper critical Re number region of smooth sphere by Taneda(1976).

著者

川那辺 洋 石山 拓二 塩路 昌宏

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.856, pp.17-00294-17-00294, 2017 (Released:2017-12-25)

参考文献数

5

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Entrainment process of surrounding fluid for a diesel spray is investigated based on the momentum theory and 1-D simple spray model developed by Musculus et. al. Entrained fluid distribution along the spray axis is theoretically estimated. The results show that the absolute value of entrainment velocity depends on axis location and is inversely proportional to the distance from the nozzle. Therefore, the large amount of entrained fluid comes from the upstream region near field of nozzle. 1-D simple spray model is performed for the same target and the effect of the injection rate on entraining process is clarified.

著者

山本 勝太 牧野 一成 石塚 弘道

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.856, pp.17-00337-17-00337, 2017 (Released:2017-12-25)

参考文献数

10

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The integrity of railway axles is a critical aspect for ensuring the safety of a railway system. Therefore, non-destructive inspections such as ultrasonic testing and magnetic particle testing are conducted periodically. Some railway operators conduct ultrasonic tests directly on axles mounted on the train. However, the axles have to be disassembled for conducting magnetic particle testing. In the present study, the effects of variable amplitude stress acting on cracks and axle bending stress during ultrasonic test on ultrasonic response are discussed. An ultrasonic test was conducted using a full-scale axle specimen that had fatigue cracks and no artificial notches. The ultrasonic response was evaluated for the cracks whose lengths were 10 mm, 16 mm, and 19 mm. Under an unloaded condition, the ultrasonic response for the 16-mm-long and 19-mm-long cracks was approximately 4 or 7 times higher than that for the 10-mm-long crack, although the cross-sectional area of each of these cracks was approximately 2.5 or 3.5 times larger than that of the 10-mm-long crack. The obtained results indicate that the contribution of the reflection area to the ultrasonic response under a variable amplitude stress differs from that under a constant stress condition. Moreover, the influence of axle bending stress ranging between -50 MPa to +47 MPa on the ultrasonic response was investigated. A higher bending stress led to a higher ultrasonic response. However, the decreasing rate of ultrasonic response caused under compressive stress was lower than the increasing rate under tensile stress. For example, the ultrasonic response was approximately 2 dB lower than that under the unloaded condition at a compressive stress of -30 MPa; however, the ultrasonic response showed an increment of approximately 4 dB at a tensile stress of 30 MPa. A similar trend was observed in the crack of each length. The results denote that the crack position influences the precision of crack detection in ultrasonic inspection. However, considering that the maximum static bending stress of axles used in Japan is 30 MPa, its effect on inservice axle inspection is negligible.