2021/08/16 更新

写真a

サカモト ジュンジ
坂本 惇司
SAKAMOTO Junji
所属
自然科学学域 助教
職名
助教
外部リンク

学位

  • 博士(工学) ( 2013年3月   九州大学 )

研究キーワード

  • 金属疲労

  • 振動

  • リスク

  • 材料力学

研究分野

  • 社会基盤(土木・建築・防災) / 社会システム工学

  • 社会基盤(土木・建築・防災) / 安全工学

  • ものづくり技術(機械・電気電子・化学工学) / 材料力学、機械材料

学歴

  • 九州大学   工学府   機械工学専攻

    2010年4月 - 2013年3月

      詳細を見る

    国名: 日本国

    researchmap

  • 九州大学   Graduate School of Engineering   Department of Mechanical Engineering Science

    2009年4月 - 2010年3月

      詳細を見る

    国名: 日本国

    researchmap

  • 九州大学   工学部   機械航空工学科

    2005年4月 - 2009年3月

      詳細を見る

    国名: 日本国

    researchmap

経歴

  • 岡山大学   学術研究院自然科学学域   助教

    2021年4月 - 現在

      詳細を見る

    国名:日本国

    researchmap

  • 横浜国立大学   リスク共生社会創造センター   非常勤講師

    2018年12月 - 2019年3月

      詳細を見る

    国名:日本国

    researchmap

  • 岡山大学   大学院自然科学研究科   助教

    2018年9月 - 2021年3月

      詳細を見る

    国名:日本国

    researchmap

  • 横浜国立大学   先端科学高等研究院   助教

    2017年6月 - 2018年8月

      詳細を見る

    国名:日本国

    researchmap

  • 横浜国立大学   リスク共生社会創造センター   助教

    2015年10月 - 2017年5月

      詳細を見る

    国名:日本国

    researchmap

  • 横浜国立大学   安心・安全の科学研究教育センター   研究員

    2014年11月 - 2015年9月

      詳細を見る

    国名:日本国

    researchmap

  • ソウル科学技術大学   自動車&機械工学部門   客員教員

    2013年5月 - 2014年10月

      詳細を見る

    国名:大韓民国

    researchmap

  • 九州大学   工学研究院機械工学部門   学術研究員

    2013年4月 - 2013年8月

      詳細を見る

    国名:日本国

    researchmap

▼全件表示

所属学協会

 

論文

  • Effect of resin lamination on tensile strength characteristics of SUS304 stainless steel thin film 査読

    Junji Sakamoto, Naoya Tada, Takeshi Uemori

    The International Journal of Advanced Manufacturing Technology   116 ( 3-4 )   1081 - 1088   2021年9月

     詳細を見る

    担当区分:筆頭著者, 責任著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The objective of this study is to clarify the effect of resin lamination on the tensile strength characteristics of SUS304 stainless steel thin films. We conducted tensile and stepwise tensile tests using several types of specimens prepared with 20-μm- and 40-μm-thick SUS304 films, 25-μm-thick polypropylene (PP) film, and 6-μm-thick polyethylene terephthalate (PET) film. Their macroscopic and microscopic tensile deformation behaviors were observed using an optical microscope and a reflection-configured digital holographic microscope, respectively. As a result, laminating the PP or PET films onto the SUS film did not significantly change the macroscopic and microscopic strain changes against the tensile load or microscopic surface changes in the low-strain region. Laminating the PET film onto the SUS film did not reduce the fracture strain, whereas laminating the PP film onto the SUS film did reduce it. One of the reasons may be that burrs formed on the side surface of the PP/SUS laminate. Polishing the side surface of the PP/SUS laminate may suppress the reduction in its fracture strain. The reduction of the fracture strain due to the PP lamination in the 20 μm thick SUS film was larger than that of the 40-μm-thick SUS film. In thin SUS films, small stress concentrators that have almost no effect on macroscopic and microscopic deformation might significantly reduce the fracture strain.

    DOI: 10.1007/s00170-021-07510-8

    Scopus

    researchmap

  • Prediction of the fracture location by tensile tests of gray cast iron based on the dimensional changes of graphite flakes

    Naoya Tada, Takeshi Uemori, Junji Sakamoto

    Journal of Pressure Vessel Technology, Transactions of the ASME   143 ( 2 )   2021年4月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2021 American Society of Mechanical Engineers (ASME). All rights reserved. Gray cast iron has been used as a component in various mechanical parts, such as the blocks and heads of automobile and marine engines, cylinder liners for internal combustion engines, and machine tool bases. It is desirable because of its good castability and machinability, damping characteristics, and high performance-To-cost ratio. On the other hand, weak graphite flakes present in gray cast iron serve as stress concentrators and adversely affect the material strength. Therefore, it is crucial to examine the relationship between the distribution of graphite flakes and the strength or fracture of gray cast iron. In this study, tensile tests on gray cast iron were carried out using a plate specimen and observed by scanning electron microscopy, and the microscopic deformation was observed on the specimen surface. Particularly, the change in the size of graphite flakes during the tensile tests was examined, and the observed trend was discussed. The experimental results reveal that the dimensional changes in the graphite flakes vary in the observed area and that the final fracture occurs in an area where a large dimensional change is observed, suggesting that the fracture location or critical parts of gray cast iron can be predicted from the dimensional changes of the graphite flakes at an early stage of deformation.

    DOI: 10.1115/1.4048063

    Scopus

    researchmap

  • Finite element study of the effect of internal cracks on surface profile change due to low loading of turbine blade 査読

    Junji Sakamoto, Naoya Tada, Takeshi Uemori, Hayato Kuniyasu

    Applied Sciences (Switzerland)   10 ( 14 )   2020年7月

     詳細を見る

    担当区分:筆頭著者, 責任著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    © 2020 by the authors. Turbine blades for thermal power plants are exposed to severe environments, making it necessary to ensure safety against damage, such as crack formation. A previous method detected internal cracks by applying a small load to a target member. Changes in the surface properties of the material were detected before and after the load using a digital holographic microscope and a digital height correlation method. In this study, this technique was applied in combination with finite element analysis using a 2D and 3D model simulating the turbine blades. Analysis clarified that the change in the surface properties under a small load varied according to the presence or absence of a crack, and elucidated the strain distribution that caused the difference in the change. In addition, analyses of the 2D model considering the material anisotropy and thermal barrier coating were conducted. The difference in the change in the surface properties and strain distribution according to the presence or absence of cracks was elucidated. The difference in the change in the top surface height distribution of the materials with and without a crack was directly proportional to the crack length. As the value was large with respect to the vertical resolution of 0.2 nm of the digital holographic microscope, the change could be detected by the microscope.

    DOI: 10.3390/app10144883

    Scopus

    researchmap

  • Leak frequency analysis for hydrogen-based technology using bayesian and frequentist methods 査読

    Mahesh Kodoth, Shu Aoyama, Junji Sakamoto, Naoya Kasai, Yehia Khalil, Tadahiro Shibutani, Atsumi Miyake

    Process Safety and Environmental Protection   136   148 - 156   2020年4月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2020 Institution of Chemical Engineers Dealing with hazardous environments such as hydrogen poses considerable risks to property, people, and the environment. Leak frequency analysis is a method of understanding the characteristics of risks at hydrogen refueling stations (HRSs). This paper proposes leak rate estimation using time-based evaluation methods that utilize historical HRS accident information. In addition, leak frequency estimates from another two methods (non-parametric and leak-hole-size) were examined. In the non-parametric approach, the leak frequency is estimated based on a Bayesian update. The results from these three approaches are summarized to understand the trend of leak rate data. The leak rate data from the time-based method displays a similar trend to the leak size based method. However, the non-parametric method tends to be conservative due to high failure observations (new evidences) during the Bayesian update. Finally, the unrevealed leak time was calculated as a function of the leak frequency. The quantitative insights of this study can be used to set performance standards for the availability and reliability in the operation and maintenance of HRSs.

    DOI: 10.1016/j.psep.2020.01.025

    Scopus

    researchmap

  • 引張および疲労負荷を受ける純チタン細線の破壊予測に向けた直流電位差および直径分布の変化の分析 査読

    坂本 惇司, 高木 佑輔, 上森 武, 多田 直哉

    日本機械学会論文集   86 ( 882 )   19 - 00351-19-00351   2020年2月

     詳細を見る

    担当区分:筆頭著者, 責任著者   記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:一般社団法人 日本機械学会  

    <p>Pure titanium thin wires have been used for medical fields. It is important to investigate the possibility of non-destructive inspection of pure titanium thin wires for the safety utilization of them. In order to investigate a fracture prediction method for a pure titanium thin wire, we performed tensile and fatigue tests and a finite element analysis to analyze the changes of direct current potential difference and diameter distribution of the pure titanium thin wire during tensile and fatigue tests. It was found that a direct current potential difference method may be available for evaluating the tensile and fatigue damages of the pure titanium thin wire. In the tensile and fatigue tests, the normalized direct current potential difference increased almost linearly with an increase in the nominal strain, and a sign of an increase of the normalized direct current potential difference was observed when the fatigue crack propagated. Therefore, the nondestructive inspection could be conducted by setting a tolerance value of the normalized direct current potential difference, or detecting a sign of an increase in the normalized direct current potential difference. In addition, a method of predicting the fracture location from the diameter distribution change of the pure titanium thin wire was studied. The method could be applied to tensile and fatigue fractures.</p>

    DOI: 10.1299/transjsme.19-00351

    CiNii Article

    researchmap

  • How knowledge about or experience with hydrogen fueling stations improves their public acceptance 査読

    Shunichi Hienuki, Yoshie Hirayama, Tadahiro Shibutani, Junji Sakamoto, Jo Nakayama, Atsumi Miyake

    Sustainability (Switzerland)   11 ( 22 )   2019年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    © 2019 by the authors. Hydrogen, which is expected to be a popular type of next-generation energy, is drawing attention as a fuel option for the formation of a low-carbon society. Because hydrogen energy is different in nature from existing energy technologies, it is necessary to promote sufficient social recognition and acceptability of the technology for its widespread use. In this study, we focused on the effect of initiatives to improve awareness of hydrogen energy technology, thereby investigating the acceptability of hydrogen energy to those participating in either several hydrogen energy technology introduction events or professional seminars. According to the survey results, participants in the technology introduction events tended to have lower levels of hydrogen and hydrogen energy technology knowledge than did participants in the hydrogen-energy-related seminars, but confidence in the technology and acceptability of the installation of hydrogen stations near their own residences tended to be higher. It was suggested that knowledge about hydrogen and technology could lead to improved acceptability through improved levels of trust in the technology. On the other hand, social benefits, such as those for the environment, socioeconomics, and energy security, have little impact on individual levels of acceptance of new technology.

    DOI: 10.3390/su11226339

    Scopus

    researchmap

  • Prediction of fracture location in tensile test of short-fiber-self-reinforced polyethylene composite plates 査読

    Naoya Tada, Ming Jin, Takeshi Uemori, Junji Sakamoto

    American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP   3   2019年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2019 ASME Composite materials such as carbon-fiber-reinforced plastics (CFRP) and glass-fiber-reinforced plastics (GFRP) have been attracting much attention from the viewpoint of lightweight solution of automobiles and airplanes. However, the recyclability of these composite materials is not sufficient and the environmental load is large. Recently, self-reinforced polymer (SRP), in which similar polymer is used for reinforcing fibers and matrix, has been proposed. High-density polyethylene (HDPE) reinforced with ultra-high-molecular-weight polyethylene (UHMWPE) fibers, so-called self-reinforced PE (SRPE), is one of the promising thermoplastic composites. In this study, SRPE plates were made and the tensile tests were carried out. After the effect of reinforcement of UHMWPE fibers was evaluated on the basis of the tensile strength, the relationship between the distribution of UHMWPE fibers and the location of the final fracture line was examined. It was found from these experimental results that the fracture tends to occur along the regions with low area fraction of fibers or along those with low area fraction of fiber/matrix boundaries. This fact suggests that the fracture location of SRPs is predictable from the distribution of reinforcing fibers.

    DOI: 10.1115/PVP2019-93546

    Scopus

    researchmap

  • Analysis of fatigue damage of aluminium alloy under multiaxial random vibration 査読

    Junji Sakamoto, Tadahiro Shibutani

    Procedia Structural Integrity   13   529 - 534   2018年12月

     詳細を見る

    担当区分:筆頭著者, 責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    DOI: 10.1016/j.prostr.2018.12.087

    Web of Science

    researchmap

  • Evaluating uncertainty in accident rate estimation at hydrogen refueling station using time correlation model 査読

    Mahesh Kodoth, Shu Aoyama, Junji Sakamoto, Naoya Kasai, Tadahiro Shibutani, Atsumi Miyake

    International Journal of Hydrogen Energy   43 ( 52 )   23409 - 23417   2018年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    © 2018 Hydrogen Energy Publications LLC Hydrogen, as a future energy carrier, is receiving a significant amount of attention in Japan. From the viewpoint of safety, risk evaluation is required in order to increase the number of hydrogen refueling stations (HRSs) implemented in Japan. Collecting data about accidents in the past will provide a hint to understand the trend in the possibility of accidents occurrence by identifying its operation time However, in new technology; accident rate estimation can have a high degree of uncertainty due to absence of major accident direct data in the late operational period. The uncertainty in the estimation is proportional to the data unavailability, which increases over long operation period due to decrease in number of stations. In this paper, a suitable time correlation model is adopted in the estimation to reflect lack (due to the limited operation period of HRS) or abundance of accident data, which is not well supported by conventional approaches. The model adopted in this paper shows that the uncertainty in the estimation increases when the operation time is long owing to the decreasing data.

    DOI: 10.1016/j.ijhydene.2018.10.175

    Scopus

    researchmap

  • Evaluation of safety measures of a hydrogen fueling station using physical modeling 査読

    Junji Sakamoto, Hitoshi Misono, Jo Nakayama, Naoya Kasai, Tadahiro Shibutani, Atsumi Miyake

    Sustainability (Switzerland)   10 ( 11 )   2018年10月

     詳細を見る

    担当区分:筆頭著者, 責任著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    © 2018 by the authors. Hydrogen fueling stations are essential for operating fuel cell vehicles. If multiple safety measures in a hydrogen fueling station fail simultaneously, it could lead to severe consequences. To analyze the risk of such a situation, we developed a physical model of a hydrogen fueling station, which, when using, the temperature, pressure, and flow rate of hydrogen could be simulated under normal and abnormal operating states. The physical model was validated by comparing the analytical results with the experimental results of an actual hydrogen fueling station. By combining the physical model with a statistical method, we evaluated the significance of the safety measures in the event wherein multiple safety measures fail simultaneously. We determined the combinations of failures of safety measures that could lead to accidents, and suggested a measure for preventing and mitigating the accident scenario.

    DOI: 10.3390/su10113846

    Scopus

    researchmap

  • Potential failure mode identification of operational amplifier circuit board by using high accelerated limit test 査読

    Junji Sakamoto, Ryoma Hirata, Tadahiro Shibutani

    Microelectronics Reliability   85   19 - 24   2018年6月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier Ltd  

    In this study, the potential failure modes of a small operational amplifier circuit board were investigated. The high accelerated limit test (HALT) was employed to identify the failure modes under multi-axial vibration and temperature loadings. Five stress tests, specifically, low and high temperature, vibration, thermal shock, and composite profiles were performed. An aluminum electrolytic capacitor was damaged under the low temperature process, whereas the capacitance of a ceramic capacitor decreased under the high temperature process. The vibration test revealed that mechanical fatigue occurs at the terminal leads of aluminum electrolytic capacitors. The HALT also revealed coupled effects between high and low temperature processes and vibration.

    DOI: 10.1016/j.microrel.2018.04.005

    Scopus

    researchmap

  • Effects of the shape of small flaws and damage due to a focused ion beam on the fatigue strength characteristics of annealed medium‑carbon steel 査読

    Junji Sakamoto, Shigeru Hamada, Hiroshi Noguchi

    Engineering Failure Analysis   87   49 - 68   2018年5月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    © 2018 Elsevier Ltd Fatigue tests and hardness tests were conducted in order to clarify the effects of the shapes of small flaws and damage caused by a focused ion beam (FIB) on the fatigue strength characteristics of annealed medium‑carbon steel. The notch root radius of the flaw at the branch point dominates the type of the fatigue limit and was found to be approximately 50 μm, a value that was significantly smaller than the 500 μm of two-dimensional notches in steel. The effect of the FIB-damaged layer on fatigue crack initiation from the FIB-milled notch in the steel was negligible. Moreover, the present study indicated that the effect of the FIB-damaged layer on the fatigue crack initiation at the FIB-milled notch could be evaluated simply by using a hardness test for the other materials and FIB conditions.

    DOI: 10.1016/j.engfailanal.2018.02.005

    Scopus

    researchmap

  • 水素ステーションのリスク評価と社会実装

    三宅 淳巳, 坂本 惇司

    空気清浄 : コンタミネーションコントロール   55 ( 5 )   311 - 318   2018年

     詳細を見る

    記述言語:日本語   出版者・発行元:日本空気清浄協会  

    CiNii Article

    researchmap

  • Applying a comprehensive societal risk framework to hydrogen fueling stations

    Atsumi Miyake, Junji Sakamoto, Shunichi Hienuki, Jo Nakayama, Yu Ichiro Izato, Kazuhiko Noguchi

    Global Congress on Process Safety 2018, GCPS 2018 - Topical Conference at the 2018 AIChE Spring Meeting and 14th Global Congress on Process Safety   4   2538 - 2547   2018年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    © GCPS 2018.All right reserved. New perspectives on a comprehensive societal risk framework for technological systems are introduced and discussed in relation to an example application involving a hydrogen fueling station for fuel cell vehicles. The comprehensive societal risk framework consists of not only technological and economic risks, but also environmental and societal risks. This framework will be indispensable to risk communication efforts and initiatives to foster the public acceptance of technological systems.

    Scopus

    researchmap

  • Finite element analysis of thermal and mechanical stresses due to the grain anisotropy of polycrystalline β-Sn 査読

    Junji Sakamoto, Hisakazu Ohara, Tadahiro Shibutani

    Microelectronics Reliability   71   29 - 34   2017年4月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    © 2017 Elsevier Ltd In order to investigate the stress and strain distributions caused by the grain anisotropy of polycrystalline β-Sn, a finite-element (FE) analysis was conducted using a polycrystalline model that considers the effect of grain anisotropy on the elastic and plastic properties. Even in the case of thermal free expansion with a temperature change of 75 °C, plastic strains can be generated locally in polycrystalline β-Sn. This might be due to the high anisotropy of the thermal expansion coefficient and the low yield strength of β-Sn. It was found that both in-phase and out-of-phase thermal stresses can be present in the polycrystalline β-Sn simultaneously. The highest stress and strain appeared in the grains whose orientation is relatively different from those of neighboring grains, near the grain boundaries. This might cause the formation of a grain boundary void in the Pb-free solder. Comparing the strain distribution due to the thermal expansion coefficient anisotropy and the Young&#039;s modulus anisotropy, it was determined that the maximum value of the plastic strain due to the thermal expansion coefficient anisotropy is approximately 10% higher than that due to the anisotropy of Young&#039;s modulus, and the high strain areas are also different in the two cases. The thermo-mechanical fatigue life of β-Sn might be shorter than that estimated using the isothermal low cycle fatigue life at the same level as the macroscopic strain and could not be estimated by the previous method.

    DOI: 10.1016/j.microrel.2017.02.009

    Web of Science

    Scopus

    researchmap

  • Simulation-based safety investigation of a hydrogen fueling station with an on-site hydrogen production system involving methylcyclohexane 査読

    Jo Nakayama, Hitoshi Misono, Junji Sakamoto, Naoya Kasai, Tadahiro Shibutani, Atsumi Miyake

    International Journal of Hydrogen Energy   42 ( 15 )   10636 - 10644   2017年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Adequate safety measures are crucial for preventing major accidents at hydrogen fueling stations. In particular, risk analysis of the domino effect at hydrogen fueling stations is essential because knock-on accidents are likely to intensify the consequences of a relatively small incident. Several risk assessment studies have focused on hydrogen fueling stations, but none have investigated accidental scenarios related to the domino effect at such stations. Therefore, the purpose of this study is to identify a domino effect scenario, analyze the scenario by using simulations and propose safety measures for preventing and mitigating of the scenario. In this hazard identification study, we identified the domino effect scenario of a hydrogen fueling station with an on-site hydrogen production system involving methylcyclohexane and investigated through simulations of the scenario. The simulations revealed that a pool fire of methylcyclohexane or toluene can damage the process equipment and that thermal radiation may cause the pressurized hydrogen tanks to rupture. The rupture-type vent system can serve as a critical safety measure for preventing and mitigating the examined scenario. (C) 2016 The Authors. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

    DOI: 10.1016/j.ijhydene.2016.11.072

    Web of Science

    Scopus

    researchmap

  • 社会総合リスクの視点から見た水素エネルギーキャリアの安全性評価 (特集 事故を未然に防ぐ取り組み)

    中山 穣, 稗貫 峻一, 坂本 惇司, 笠井 尚哉, 澁谷 忠弘, 野口 和彦, 三宅 淳巳

    水素エネルギーシステム = Journal of the Hydrogen Energy Systems Society of Japan   42 ( 3 )   138 - 144   2017年

     詳細を見る

    記述言語:日本語   出版者・発行元:水素エネルギー協会  

    CiNii Article

    researchmap

  • Leakage-type-based analysis of accidents involving hydrogen fueling stations in Japan and USA 査読

    Junji Sakamoto, Ryunosuke Sato, Jo Nakayama, Naoya Kasai, Tadahiro Shibutani, Atsumi Miyake

    International Journal of Hydrogen Energy   41 ( 46 )   21564 - 21570   2016年12月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    To identify the safety issues associated with hydrogen fueling stations, incidents at such stations in Japan and the USA were analyzed considering the regulations in these countries. Leakage due to the damage and fracture of main bodies of apparatuses and pipes in Japan and the USA is mainly caused by design error, that is, poorly planned fatigue. Considering the present incidents in these countries, adequate consideration of the usage environment in the design is very important. Leakage from flanges, valves, and seals in Japan is mainly caused by screw joints. If welded joints are to be used in hydrogen fueling stations in Japan, strength data for welded parts should be obtained and pipe thicknesses should be reduced. Leakage due to other factors, e.g., external impact, in Japan and the USA is mainly caused by human error. To realize self-serviced hydrogen fueling stations, safety measures should be developed to prevent human error by fuel cell vehicle users. (C) 2016 The Authors. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

    DOI: 10.1016/j.ijhydene.2016.08.060

    Web of Science

    Scopus

    researchmap

  • Preliminary hazard identification for qualitative risk assessment on a hybrid gasoline-hydrogen fueling station with an on-site hydrogen production system using organic chemical hydride 査読

    Jo Nakayama, Junji Sakamoto, Naoya Kasai, Tadahiro Shibutani, Atsumi Miyake

    International Journal of Hydrogen Energy   41 ( 18 )   7518 - 7525   2016年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Hydrogen infrastructures are important for the commercialization of fuel cell vehicles. Hydrogen storage and transportation are significant topics because it is difficult to safely and effectively treat large amounts of hydrogen because of hydrogen hazards. An organic chemical hydride method keeps and provides hydrogen using hydrogenation and dehydrogenation chemical reactions with aromatic compounds. This method has advantages in that the conventional petrochemical products are used as a hydrogen carrier, and petrochemicals are more easily treated than hydrogen because of low hazards. Hydrogen fueling stations are also crucial infrastructures for hydrogen supply. In Japan, hybrid gasoline hydrogen fueling stations are needed for effective space utilization in urban areas. It is essential to address the safety issues of hybrid fueling stations for inherently safer station construction. We focused on a hybrid gasoline-hydrogen fueling station with an on-site hydrogen production system using methylcyclohexane as an organic chemical hydride. The purpose of this study is to reveal unique hybrid risks in the station with a hazard identification study (HAZID study). As a result of the HAZID study, we identified 314 accident scenarios involving gasoline and organic chemical hydride systems. In addition, we suggested improvement safety measures for uniquely worst-case accident scenarios to prevent and mitigate the scenarios. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2016.03.143

    Web of Science

    Scopus

    researchmap

  • Effect of gasoline pool fire on liquid hydrogen storage tank in hybrid hydrogen-gasoline fueling station 査読

    Junji Sakamoto, Jo Nakayama, Toyoaki Nakarai, Naoya Kasai, Tadahiro Shibutani, Atsumi Miyake

    International Journal of Hydrogen Energy   41 ( 3 )   2096 - 2104   2016年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Multiple-energy-fueling stations, which can supply several types of energy such as gasoline, CNG, and hydrogen, could guarantee the efficient use of space. To guide the safety management of hybrid hydrogen gasoline fueling stations, which utilize liquid hydrogen as an energy carrier, the scale of gasoline pool fires was estimated using the hazard assessment tool Toxic Release Analysis of Chemical Emissions (TRACE). Subsequently, the temperature and the stress due to temperature distribution were estimated using ANSYS. Based on the results, the safety of liquid hydrogen storage tanks was discussed. It was inferred that the emissivity of the outer material of the tank and the safety distance between liquid hydrogen storage tanks and gasoline dispensers should be less than 0.2 and more than 8.5 m, respectively, to protect the liquid hydrogen storage tank from the gasoline pool fire. To reduce the safety distance, several measures are required, e.g. additional thermal shields such as protective intumescent paint and water sprinkler systems and an increased slope to lead gasoline off to a safe domain away from the liquid hydrogen storage tank. Copyright (C) 2015, The Authors. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications, LLC.

    DOI: 10.1016/j.ijhydene.2015.11.039

    Web of Science

    Scopus

    researchmap

  • Risk assessment for a gas and liquid Hydrogen fueling station 査読

    Jo Nakayama, Junji Sakamoto, Naoya Kasai, Tadahiro Shibutani, Atsumi Miyake

    49th Annual Loss Prevention Symposium 2015, LPS 2015 - Topical Conference at the 2015 AIChE Spring Meeting and 11th Global Congress on Process Safety   138 - 150   2015年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    Hydrogen fueling stations are critical infrastructure for facilitating the commercialization of fuel cell vehicles (FCVs). In Japan, few hydrogen fueling stations have been built but several are under design or construction stages. It will be difficult to construct stand-alone hydrogen fueling stations in many locations in Japan because of the narrow spaces in urban cities. Therefore, hybrid stations with gasoline and hydrogen supply systems will be constructed to effectively use small spaces. Safety measures must be incorporated into the stations. Although stand-alone hydrogen fueling stations using compressed and liquid hydrogen have been investigated with risk assessment, the hybrid gasoline-hydrogen fueling stations have not been analyzed yet. This paper presents risk assessment from a Hazard Identification Study (HAZID) for identification of inherent accident scenarios and risks relating to gasoline and hydrogen supply systems. The study shows that HAZID was an effective assessment tool because it indicated similar accident scenarios analyzed by HAZOP and FMEA. Furthermore, HAZID revealed inherent scenarios and risks.

    Scopus

    researchmap

  • Effect of surface flaw on fatigue strength of shot-peened medium-carbon steel 査読

    Junji Sakamoto, Yong-Sung Lee, Seong-Kyun Cheong

    Engineering Fracture Mechanics   133   99 - 111   2015年1月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The effect of surface flaw on fatigue strength of shot-peened medium-carbon steel was experimentally studied. The fatigue crack initiation life, fatigue crack growth life, and fatigue limit in the steel can be increased by using shot peening (SP). The fatigue fracture of SP specimen occurred by the propagations and coalescence of fatigue cracks initiated from the initial cracks due to SP. The fatigue limit of SP specimen was determined by the propagation limit of fatigue crack. When the size of surface flaw is sufficiently small compared to the SP affected zone, the flaws have not significantly changed the fatigue strength of the SP specimens. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.engfracmech.2014.11.005

    Web of Science

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • Effect of shot peening coverage on fatigue limit in round bar of annealed medium carbon steel 査読

    Junji Sakamoto, Yong-Sung Lee, Seong-Kyun Cheong

    Journal of Mechanical Science and Technology   28 ( 9 )   3555 - 3560   2014年9月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:KOREAN SOC MECHANICAL ENGINEERS  

    Shot peening is an effective and economical technique for improving the fatigue strength of metallic components by inducing compressive residual stress and hardening the layer near the surface. The effect is generally evaluated by main two parameters: coverage and peening intensity. However, the valuable coverage for improving the fatigue strength depends on the shape of the target material. In this study, the effect of coverage on fatigue limit in round bar of annealed medium carbon steel was experimentally studied. The fatigue limits for shot peened round bar specimens with 140-2300% coverage increased 14-25% by comparing those for non-peened round bar specimens. The valuable range of coverage was 280-60% in the used material and shot peening condition for improving the fatigue limit in short time. The result indicates that the valuable coverage of the round bar material is higher than full coverage to improve the fatigue limit of the material due to the effect of incident angle on round bar, even though the degree depends on the materials and shot peening conditions.

    DOI: 10.1007/s12206-014-0816-9

    Web of Science

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • Role of eutectic silicon particles in fatigue crack initiation and propagation and fatigue strength characteristics of cast aluminum alloy A356 査読

    Lei Zeng, Junji Sakamoto, Atsushi Fujii, Hiroshi Noguchi

    Engineering Fracture Mechanics   115   1 - 12   2014年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The cast aluminum alloy A356 was studied to observe the effects of the eutectic silicon particles on its fatigue strength characteristics and the initiation and propagation of fatigue cracks. Two mechanisms of the initiation of the fatigue cracks were observed in the low-cycle fatigue regime, and only one in the high-cycle fatigue regime. A small fatigue life scatter was also found to be characteristics of the specimens of the alloys. Furthermore, the existence of a fatigue limit in the alloy is discussed. (C) 2013 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.engfracmech.2013.11.016

    Web of Science

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • Method for Assessing Applicability of an Artificial Flaw as a Small Initial Crack for Fatigue Limit Evaluation and Its Application to a Drill Hole and an FIB Processed Sharp Notch in Annealed 0.45% Carbon Steel 査読

    Junji Sakamoto, Yoshimasa Takahashi, Yuuta Aono, Hiroshi Noguchi

    Journal of Testing and Evaluation   41 ( 2 )   194 - 199   2013年3月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER SOC TESTING MATERIALS  

    In this study, we propose a method for assessing the applicability of an artificial flaw as a small initial crack for fatigue limit evaluation. The proposed method is applied to drill holes and sharp notches introduced using a focused ion beam (FIB) technique in annealed 0.45% carbon steel. It is found that under rotating bending fatigue, an FIB notch can be used as a small initial crack for fatigue limit evaluation, whereas a drill hole cannot, for root area of 50 mu m. Here, root area is the square root of the area obtained by projecting the defect onto a plane perpendicular to the load axial direction. The results indicate that an FIB notch can be used as a small initial crack for fatigue limit evaluation in a greater number of materials than those in which a drill hole can be used.

    DOI: 10.1520/JTE20120176

    Web of Science

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • Small fatigue crack growth behavior from artificial notch with focused ion beam in annealed 0.45% carbon steel 査読

    Junji Sakamoto, Yoshimasa Takahashi, Hiroshi Noguchi

    Key Engineering Materials   488-489   319 - +   2011年9月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    The aim of this study is firstly to investigate the applicability of a sharp notch with Focused Ion Beam (FIB) as a crack for fatigue limit evaluation. Secondly we investigate a condition in which artificial defects (drilled hole, FIB notch) can be used as a crack for fatigue limit evaluation. To achieve the aim, the growth behaviors and the non-propagating crack sizes of small fatigue cracks initiated from a FIB notch and a drilled hole are carefully compared with those of an annealed fatigue crack which imitates an ideally sharp crack. The results show that a FIB notch can be used as a crack for fatigue limit evaluation under some conditions. The results also show that the condition which controls the applicability of an artificial defect as an ideal crack for fatigue limit evaluation is strongly dependent on the relation between (i) the length of a non-propagating fatigue crack and (ii) the crack length when the small fatigue crack growth behaviors from an artificial defect and an ideal pre-crack become almost the same. It is found that the length of (ii) can be obtained by the analyses using the number of cycles from a certain crack length to failure.

    DOI: 10.4028/www.scientific.net/KEM.488-489.319

    Web of Science

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • Effect of hydrogen on dislocation structures around a mixed-mode fatigue crack tip in a single-crystalline iron silicon alloy 査読

    Yoshimasa Takahashi, Junji Sakamoto, Masaki Tanaka, Kenji Higashida, Hiroshi Noguchi

    Scripta Materialia   64 ( 8 )   721 - 724   2011年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The effect of hydrogen on dislocation structures around a mixed-mode fatigue crack tip in a single-crystalline iron silicon alloy was investigated by cross-sectional electron backscatter diffraction and high-voltage electron microscopy. In contrast to the previously reported results in an inert environment, no dislocation cells were formed around the crack tip in a hydrogen environment. The microscopic features around the crack tip suggest that hydrogen promotes a mode I-type crack growth mechanism, which reasonably explains the observed macroscopic crack growth property. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.scriptamat.2010.12.032

    Web of Science

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • Characterization of dislocation structures around a mixed-mode fatigue crack tip in a single-crystalline iron-silicon alloy 査読

    Yoshimasa Takahashi, Junji Sakamoto, Masaki Tanaka, Kenji Higashida, Hiroshi Noguchi

    Scripta Materialia   64 ( 2 )   157 - 160   2011年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Dislocation structures around a mixed-mode fatigue crack tip introduced into a single-crystalline iron silicon alloy is characterized by cross-sectional electron backscatter diffraction and high-voltage electron microscopy. The results show that the crack growth is preceded by the formation of a cell band and the crack grows along cell boundaries. Crack growth rate and width of the cell band are constant despite the monotonic increase in stress intensity, which is anomalous in terms of the conventional fracture mechanics concept. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.scriptamat.2010.09.033

    Web of Science

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • Fe‐3.2wt.%Si合金単結晶の傾斜疲労き裂先端における繰返し変形におよぼす水素の影響のTEM解析 査読

    高橋可昌, 坂本惇司, 田中將己, 東田賢二, 野口博司

    日本機械学会論文集 A編   76 ( 767 )   1002 - 1004   2010年7月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1299/kikaia.76.1002

    Scopus

    J-GLOBAL

    researchmap

  • Fe‐3.2wt.%Si合金単結晶の傾斜疲労き裂先端における繰返し変形のTEM観察 査読

    高橋可昌, 坂本惇司, 田中將己, 東田賢二, 野口博司

    日本機械学会論文集 A編   76 ( 762 )   251 - 253   2010年2月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1299/kikaia.76.251

    Scopus

    J-GLOBAL

    researchmap

  • Effect of gaseous hydrogen on cyclic slip behavior around a stage i fatigue crack tip in an iron alloy 査読

    Takahashi Y, Sakamoto J, Tanaka M, Higashida K, Noguchi H

    18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale   2010年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    Scopus

    researchmap

    その他リンク: http://orcid.org/0000-0002-4982-257X

▼全件表示

書籍等出版物

  • 水素利用技術集成 Vol.5 ~水素ステーション・設備の安全性~

    坂本惇司, 三宅淳巳( 担当: 分担執筆 ,  範囲: 第3章 第7節)

    エヌ・ティー・エス  2018年12月 

     詳細を見る

  • リスク共生学 先端科学でつくる暮らしと新たな社会

    三宅淳巳, 坂本惇司( 担当: 分担執筆 ,  範囲: 6.4節)

    丸善  2018年6月 

     詳細を見る

MISC

講演・口頭発表等

  • リーン型二相ステンレス鋼板の二軸応力状態下における塑性変形挙動の実験的検討

    藤田隼輔, 上森武, 多田直哉, 坂本惇司, 石丸詠一朗

    塑性加工連合講演会講演論文集  2020年11月14日 

     詳細を見る

    開催年月日: 2020年11月14日 - 2020年11月15日

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 面内反転負荷を受けるTi-6242合金の結晶塑性均質化有限要素解析

    三井 孔佑, 上森 武, 多田 直哉, 坂本 惇司

    年次大会  2020年9月14日  一般社団法人 日本機械学会

     詳細を見る

    開催年月日: 2020年9月13日 - 2020年9月16日

    記述言語:日本語   会議種別:口頭発表(一般)  

    <p>To investigate effects of dislocation density on microscopic stress distribution and macroscopic stress-strain relation, we conducted crystal plastic homogenization finite element analysis of Ti-6242 alloy subjected to in-plane reverse loading with dislocation density calculation. As a result, Statistically Stored (SS) dislocation density increased with occurrence of slip deformation for all conditions. On the other hand, Geometrically Necessary (GN) dislocation density was less likely to accumulate at the interface in the parallel relationship between primary slip systems of hcp and bcc. Although GN dislocations only develop near the interface, a large increase in GN dislocation density affects the macroscopic stress-strain relation.</p>

    researchmap

  • L曲げ解析を用いた590MPa級高張力鋼板の応力反転変形挙動の評価

    上森武, 多田直哉, 坂本惇司, 中本浩聖, 西山大悟, 松村宗一郎, 成田忍

    日本材料学会学術講演会講演論文集  2020年5月 

     詳細を見る

    開催年月日: 2020年5月

    researchmap

  • 直流電位差法を用いたCFRP積層板の引張及び曲げ損傷の評価

    佐藤 一真, 多田 直哉, 上森 武, 坂本 惇司, 河本 詳平, 鈴木 菜摘, 高梨 正祐

    中国四国支部総会・講演会 講演論文集  2020年3月  一般社団法人 日本機械学会

     詳細を見る

    開催年月日: 2020年3月

    記述言語:日本語  

    researchmap

  • ステンレス薄板のSD効果に関する実験的検討

    柴井宏治, 上森武, 多田直哉, 坂本惇司

    材料とプロセス(CD-ROM)  2020年3月 

     詳細を見る

    開催年月日: 2020年3月

    researchmap

  • ステンレス箔の引張変形特性に及ぼす樹脂フィルムラミネートの影響

    信定宥杜, 多田直哉, 坂本惇司, 上森武

    材料とプロセス(CD-ROM)  2020年3月 

     詳細を見る

    開催年月日: 2020年3月

    researchmap

  • 積層セラミックコンデンサブロックの不均一圧縮変形に関する数値解析

    玉尾 晟次郎, 多田 直哉, 上森 武, 坂本 惇司

    中国四国支部総会・講演会 講演論文集  2020年3月  一般社団法人 日本機械学会

     詳細を見る

    開催年月日: 2020年3月

    記述言語:日本語  

    researchmap

  • 多軸ランダム振動下のアルミニウム合金の疲労強度評価

    坂本 惇司, 山田 朋佳, 多田 直哉, 上森 武, 澁谷 忠弘

    M&M材料力学カンファレンス  2019年11月4日  一般社団法人 日本機械学会

     詳細を見る

    開催年月日: 2019年11月2日 - 2019年11月4日

    記述言語:日本語   会議種別:口頭発表(一般)  

    <p>Various mechanical components are subjected to random multiaxial vibration. For their safe and effective operation, it is essential to precisely evaluate the fatigue strength of the materials under multiaxial random vibration. However, the mechanisms and evaluation methods remain unclear. In this study, we performed the multiaxial random vibration experiments using aluminum alloy A5056 specimens in order to discuss a method for evaluating the vibration fatigue strength of materials. The multiaxial random vibration experiments were conducted at an acceleration input of 70 G<sub>rms</sub> within a frequency band of 10–5000 Hz under a nitrogen gas environment at a room temperature. During the multiaxial random vibration experiments the strains of the specimen were measured using 3-axis and 1-axis strain gauges and the maximum principal strains and their directions of a fracture part were estimated. Based on the results, the method for evaluating the vibration fatigue strength of materials was discussed.</p>

    researchmap

  • オーステナイト系ステンレス鋼XM-19の疲労強度と破面解析

    坂本惇司, 山本翔太, 澁谷忠弘, 志賀優多, 竹花立美, 佐野尊

    構造物の安全性および信頼性(CD-ROM)  2019年10月 

     詳細を見る

    開催年月日: 2019年10月

    記述言語:日本語  

    researchmap

  • 低荷重負荷による表面高度変化を用いた欠陥検出法に関する検討

    坂本 惇司, 國安 隼人, 多田 直哉, 上森 武

    年次大会  2019年9月9日  一般社団法人 日本機械学会

     詳細を見る

    開催年月日: 2019年9月8日 - 2019年9月11日

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • チタン合金細線の疲労への直流電位差法の適用に関する検討

    多田 直哉, 高木 佑輔, 島田 侑紀, 上森 武, 坂本 惇司

    年次大会  2019年9月9日  一般社団法人 日本機械学会

     詳細を見る

    開催年月日: 2019年9月8日 - 2019年9月11日

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 590MPa級高張力鋼板の繰返し塑性変形挙動の実験観察とそのモデル化

    上森 武, 中本 浩聖, 多田 直哉, 坂本 惇司

    年次大会  2019年9月9日  一般社団法人 日本機械学会

     詳細を見る

    開催年月日: 2019年9月8日 - 2019年9月11日

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • Applying a comprehensive societal risk framework to hydrogen fueling stations

    Atsumi Miyake, Junji Sakamoto, Shunichi Hienuki, Jo Nakayama, Yu Ichiro Izato, Kazuhiko Noguchi

    Global Congress on Process Safety 2018, GCPS 2018 - Topical Conference at the 2018 AIChE Spring Meeting and 14th Global Congress on Process Safety  2018年 

     詳細を見る

    開催年月日: 2018年

    記述言語:英語  

    © GCPS 2018.All right reserved. New perspectives on a comprehensive societal risk framework for technological systems are introduced and discussed in relation to an example application involving a hydrogen fueling station for fuel cell vehicles. The comprehensive societal risk framework consists of not only technological and economic risks, but also environmental and societal risks. This framework will be indispensable to risk communication efforts and initiatives to foster the public acceptance of technological systems.

    researchmap

  • 590MPa級DP鋼の繰返し引張‐圧縮試験とその構成モデル

    中本浩聖, 上森武, 多田直哉, 坂本惇司, 早川邦夫

    材料とプロセス(CD-ROM)  2019年8月26日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 引張せん断試験によるアルミニウム合金/高密度ポリエチレンの接合強度評価

    多田直哉, 阿部俊太朗, 上森武, 坂本惇司

    日本材料学会学術講演会講演論文集  2019年5月24日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 多軸ランダム振動下のアルミニウム合金の応力場とそれに及ぼすショットピーニングの影響

    坂本惇司

    日本材料学会学術講演会講演論文集  2019年5月24日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 多結晶純チタンの引張りにおける結晶方位変化を考慮に入れた微視的すべり変形の評価

    佐藤宏樹, 多田直哉, 上森武, 坂本惇司

    日本金属学会講演概要(CD-ROM)  2019年3月6日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 高張力鋼板の面内繰返し応力‐ひずみ応答に与えるひずみ速度の影響

    上森武, 多田直哉, 坂本惇司, 中本浩聖, 早川邦夫

    材料とプロセス(CD-ROM)  2019年3月1日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 精密ショットピーニング処理と研磨を施した高速度工具鋼の疲労寿命

    花光崚太, KARUNATHILAKA Nuwan, 多田直哉, 上森武, 坂本惇司

    日本機械学会中国四国支部総会・講演会講演論文集(CD-ROM)  2019年 

     詳細を見る

    記述言語:日本語  

    researchmap

  • リスク共生設計の提案:極限環境試験を用いた機器の故障モード特定による機器設計

    坂本惇司, 澁谷忠弘, 伊里友一朗, 野口和彦, 中山穣, 三宅淳巳

    安全工学シンポジウム講演予稿集  2018年7月3日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 多軸ランダム振動下のアルミニウム合金の疲労破壊挙動

    坂本惇司, 澁谷忠弘

    日本材料学会学術講演会講演論文集  2018年5月25日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • HAZID studyを用いた水素ステーションの定性的リスク評価

    笠井 尚哉, 中山 穣, 坂本 惇司, 澁谷 忠弘, 三宅 淳巳

    日本機械学会年次大会  2017年9月5日 

     詳細を見る

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 物理モデリングによる水素ステーションのモデル化と事故発生時の水素漏洩量の推定

    坂本 惇司, 彌園 仁志, 中山 穣, 笠井 尚哉, 澁谷 忠弘, 三宅 淳巳

    日本機械学会年次大会  2017年9月5日 

     詳細を見る

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 微小傷から発生したき裂の応力場に及ぼす傷形状および微視組織の影響の有限要素解析

    坂本惇司, 澁谷忠弘

    日本機械学会年次大会講演論文集(CD-ROM)  2016年9月10日 

     詳細を見る

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 水素スタンドにおける継手からの水素漏洩の検討

    佐藤龍之介, 中山穣, 坂本惇司, 笠井尚哉, 澁谷忠弘, 三宅淳巳

    日本機械学会年次大会講演論文集(CD-ROM)  2016年9月10日 

     詳細を見る

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 多結晶体モデルにおける仮想的なマルテンサイト変態導入の検討

    山本翔太, 坂本惇司, 澁谷忠弘

    日本機械学会年次大会講演論文集(CD-ROM)  2016年9月10日 

     詳細を見る

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 物理モデリングを用いた水素ステーションにおける緊急時の水素放散法の評価

    彌園仁志, 坂本惇司, 中山穣, 笠井尚哉, 澁谷忠弘, 三宅淳巳

    日本機械学会年次大会講演論文集(CD-ROM)  2016年9月10日 

     詳細を見る

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 高耐熱封止樹脂の密着強度試験におけるはく離挙動と熱応力影響の解析

    平田 諒磨, 澁谷 忠弘, 坂本 惇司

    マイクロエレクトロニクスシンポジウム論文集  2016年9月8日 

     詳細を見る

    記述言語:日本語   会議種別:口頭発表(一般)  

    researchmap

  • 有機ハイドライド型水素ステーションにおける蓄圧器に及ぼすプール火災の影響

    中山穣, 彌園仁志, 坂本惇司, 半井豊明, 笠井尚哉, 澁谷忠弘, 三宅淳巳

    日本火災学会研究発表会概要集  2016年5月11日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 液化水素型水素スタンド併設給油取扱所に関するHAZID Studyを用いたSafety Critical Elementsの抽出

    中山穣, 坂本惇司, 笠井尚哉, 澁谷忠弘, 三宅淳巳

    安全工学研究発表会講演予稿集  2015年12月3日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • CNGスタンドにおけるディスペンサー周辺の防爆エリアに関する検討

    塩田謙人, 中山穣, 坂本惇司, 熊崎美枝子, 笠井尚哉, 澁谷忠弘, 三宅淳巳

    安全工学研究発表会講演予稿集  2015年12月3日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • スズおよびスズ銅合金における結晶異方性に基づく熱応力の有限要素解析

    坂本惇司, 大原久和, 澁谷忠弘

    日本機械学会M&M材料力学カンファレンス(CD-ROM)  2015年11月20日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 液化水素型水素スタンド併設給油取扱所におけるガソリン火災時の液化水素貯槽に及ぼす輻射熱の影響

    坂本惇司, 中山穣, 半井豊明, 笠井尚哉, 澁谷忠弘, 三宅淳巳

    日本機械学会年次大会講演論文集(CD-ROM)  2015年9月12日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • 液化水素型水素スタンド併設給油取扱所におけるHAZID解析とETAを用いた損傷発生確率の検討

    佐藤龍之介, 中山穣, 坂本惇司, 笠井尚哉, 澁谷忠弘, 三宅淳巳

    日本機械学会年次大会講演論文集(CD-ROM)  2015年9月12日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • S45C焼入れ焼戻し材を用いた欠陥形状が疲労き裂の停留挙動に及ぼす影響の検討

    濱野泰明, 財前賢吾, 松枝剛広, 坂本惇司, 濱田繁, 野口博司

    日本機械学会M&M材料力学カンファレンス(CD-ROM)  2013年10月10日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • Applicability of a FIB-notch as a small initial crack for fatigue limit evaluation

    Sakamoto J, Takahashi Y, Noguchi H

    19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF 2012  2012年1月1日 

     詳細を見る

    In this study, we propose a method for assessing the applicability of an artificial defect as a small initial crack for fatigue limit evaluation. The proposed method is applied to drill holes and sharp notches introduced using a focused ion beam (FIB) technique in annealed 0.45% carbon steel. It is found that under rotating bending fatigue, an FIB notch can be used as a small initial crack for fatigue limit evaluation, whereas a drill hole cannot, for of ∼50 μm. Here, is the square root of the area obtained by projecting the defect onto a plane perpendicular to the load axial direction. The results indicate that an FIB notch can be used as a small initial crack for fatigue limit evaluation in a greater number of materials than those in which a drill hole can be used.

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • FIB加工による人工欠陥を有するS45C焼鈍し材の微小疲労き裂進展挙動

    坂本惇司, 高橋可昌, 野口博司

    日本機械学会M&M材料力学カンファレンス(CD-ROM)  2011年 

     詳細を見る

    記述言語:日本語  

    researchmap

  • Effect of gaseous hydrogen on cyclic slip behavior around a stage i fatigue crack tip in an iron alloy

    Takahashi Y, Sakamoto J, Tanaka M, Higashida K, Noguchi H

    18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale  2010年12月1日 

     詳細を見る

    In order to investigate the effect of gaseous hydrogen on cyclic slip behavior around an early stage (stage Ifatigue crack tip, fatigue crack growth (FCGtests using a single-crystalline Fe-3.2wt.%Si alloy are conducted respectively in a hydrogen atmosphere and in a helium atmosphere. The cross-sectional observations of the crack tips by both electron backscatter diffraction (EBSDmethod and transmission electron microscopy (TEMsuccessfully reveal the following points. In helium atmosphere, FCG is preceded by formation of cell structures and crack propagates along cell boundaries. In hydrogen atmosphere, on the other hand, no cells are seen, and crack growth process is similar to that observed in a stage II type FCG. Crack extension resistance in hydrogen is postulated to be lower than that in helium, indicating that the mode of FCG in hydrogen is more critical than that in helium.

    researchmap

    その他リンク: http://orcid.org/0000-0002-2108-2258

  • 透過型電子顕微鏡による傾斜疲労き裂先端の微視的すべり挙動におよぼす水素の影響解析

    坂本惇司, 高橋可昌, 田中將己, 東田賢二, 野口博司

    日本材料学会学術講演会講演論文集  2010年5月21日 

     詳細を見る

    記述言語:日本語  

    researchmap

  • フレッティング疲労強度向上のための応力逃がし溝形状の最適化

    坂本惇司, 近藤良之, 久保田祐信

    日本機械学会年次大会講演論文集  2009年9月12日 

     詳細を見る

    記述言語:日本語  

    researchmap

▼全件表示

共同研究・競争的資金等の研究

  • ネッキング型破壊の抑制とコーキシング効果の応用による微小金属材料の耐疲労特性向上方法の開発

    2021年04月 - 2022年03月

    公益財団法人JKA  2021年度機械振興補助事業 個別研究 

    坂本 惇司

      詳細を見る

    担当区分:研究代表者 

    researchmap

  • 振動疲労き裂進展時の力学場の解明とピーニングによる振動疲労強度向上技術の構築

    研究課題/領域番号:20K14610  2020年04月 - 2023年03月

    日本学術振興会  科学研究費助成事業 若手研究  若手研究

    坂本 惇司

      詳細を見る

    配分額:4160000円 ( 直接経費:3200000円 、 間接経費:960000円 )

    researchmap

  • 繰返し硬さ試験による疲労寿命の簡易評価法の確立とその微小材料の疲労寿命の向上探索への応用

    2019年04月 - 2020年03月

    公益財団法人村田学術振興財団  研究助成 

    坂本 惇司

      詳細を見る

    担当区分:研究代表者  資金種別:競争的資金

    researchmap

  • 多結晶金属材料の弾性表面高度分布変化に基づく塑性不均一変形の拡大と破壊の予測

    研究課題/領域番号:18H01337  2018年04月 - 2021年03月

    日本学術振興会  科学研究費助成事業 基盤研究(B)  基盤研究(B)

    多田 直哉, 上森 武, 坂本 惇司

      詳細を見る

    配分額:17940000円 ( 直接経費:13800000円 、 間接経費:4140000円 )

    本研究の初年度にあたる平成30年度は,通常の大きさの結晶粒で構成される純チタンの平板試験片を用いて繰返し引張試験を実施し,荷重の増減とともに変化する結晶粒中心部の高度を測定した.測定には現有のデジタルホログラフィック顕微鏡(DHM)を用い,そのステージ上に小型の引張試験機を設置して試験を実施した.また,試験片測定領域内の結晶粒形状ならびに方位は,走査型電子顕微鏡およびそれに付随するEBSD装置を用いて測定した.得られた結果より,除荷を伴う繰返し引張においても,各結晶粒の弾性変形状態における高度変化と塑性変形状態における高度変化が強い相関を持つことを明らかにするとともに,その強い相関性を有するいくつかの原因について検討した.また,互いに影響を及ぼし合う結晶粒の変形について詳細に検討するため,すべり線の方向分布についても検討した.その結果,表面結晶粒のすべりは,近いすべり方向を示す複数の結晶粒が互いに影響を及ぼし合いながら進行することが明らかとなった.
    次に,結晶塑性有限要素解析に関しては,まず,二次元の多結晶体モデルを作成し,それに引張負荷を加えた場合について解析を行った.その結果,内部に存在する結晶粒の変形は,表面に存在する結晶粒の変形に大きな影響を与えること,巨視的変位が小さいときの結晶粒表面の高度分布と変位が大きいときの高度分布は相関性を有すること,等を明らかにした.二次元解析ではあるが,本解析結果は,実験より得られた各結晶粒の弾性高度変化と後続の塑性高度変化の相関が妥当であることを裏付けている.

    researchmap

  • 振動疲労強度におけるショットピーニングによる表面塑性加工の効果の検討

    2017年10月 - 2019年03月

    公益財団法人天田財団  奨励研究助成B(萌芽的研究) 

    坂本 惇司

      詳細を見る

    担当区分:研究代表者  資金種別:競争的資金

    researchmap

  • 六軸ランダム振動を受ける材料の疲労損傷メカニズムの解明と評価試験法の構築

    研究課題/領域番号:17K14556  2017年04月 - 2020年03月

    日本学術振興会  科学研究費助成事業 若手研究(B)  若手研究(B)

    坂本 惇司

      詳細を見る

    担当区分:研究代表者  資金種別:競争的資金

    配分額:4420000円 ( 直接経費:3400000円 、 間接経費:1020000円 )

    本研究では、多軸ランダム振動を受ける機械、構造物を安全かつ有効に使用することを目指し、多軸ランダム振動を受ける材料の疲労損傷メカニズム解明および評価試験法の構築を目的としている。
    初年度は、アルミニウム合金A5056を供試材としたボタンヘッド型試験片を用いて10 Grmsから70 Grmsまでの異なる重力加速度の多軸ランダム振動試験を実施した。その結果、多軸ランダム振動を受ける材料であっても一軸方向の負荷によって疲労破壊が起こる可能性や修正マイナー則を用いた疲労寿命の評価の可能性を示した。
    本年度は、初年度と同様の供試材であるアルミニウム合金A5056において、異なる形状のY字型試験片を用いて10 Grmsから70 Grmsまでの異なる重力加速度の多軸ランダム振動試験を実施した。振動試験中には、破壊起点と予想される部分の力学場を測定するため、3軸ひずみゲージを用いて測定した。その結果、主応力の大きさ、方向、負荷周波数を明らかにした。具体的には、多軸ランダム振動を受ける材料であっても一つの振動モードが支配的であり、主応力の方向および負荷周波数はほぼ一定であり、主応力の大きさは分布をもつことが分かった。また、主応力の方向と負荷周波数は重力加速度によらずほぼ一定であり、主応力の大きさは重力加速度によって増加した。これは、初年度の実験結果と同様の傾向であり、上記の結果は、材料の形状にあまり依存しない可能性が示唆された。さらに、この結果を基に、疲労寿命の評価方法について考察した。

    researchmap

▼全件表示

 

担当授業科目

  • 創造工学実験 (2021年度) 1~4学期  - [第1学期]火5,火6,火7,火8, [第2学期]その他, [第3学期]火5,火6,火7,火8, [第4学期]火5,火6,火7,火8

  • 創造工学実験 (2021年度) 1~4学期  - [第1学期]火5,火6,火7,火8, [第2学期]その他, [第3学期]火5,火6,火7,火8, [第4学期]火5,火6,火7,火8

  • 創造工学実験Ⅱ (2021年度) 3・4学期  - 火5,火6,火7,火8

  • 創造工学実験I (2021年度) 第1学期  - 火5,火6,火7,火8

  • 機械システム工学演習1 (2021年度) 前期  - その他

  • 機械システム工学演習2 (2021年度) 後期  - その他

  • 創造工学実験 (2020年度) 1~4学期  - 火5,火6,火7,火8

  • 創造工学実験 (2020年度) 1~4学期  - 火5,火6,火7,火8

  • 創造工学実験Ⅱ (2020年度) 3・4学期  - 火5,火6,火7,火8

  • 創造工学実験I (2020年度) 第1学期  - 火5,火6,火7,火8

  • 機械システム工学セミナーⅡ (2020年度) 第3学期  - 水5,水6,水7,水8

  • 機械システム工学セミナーⅡ (2020年度) 第3学期  - 水5,水6,水7,水8

▼全件表示