2025年05月, 公益社団法人 日本材料学会, 日本材料学会疲労部門委員会（令和6年度）論文賞　　　　　　　　　　　　　　　
Full-life growth behavior of a naturally initiated internal fatigue crack in beta titanium alloy via in situ synchrotron radiation multiscale tomography
Gaoge Xue;Takashi Nakamura;Nao Fujimura;Kosuke Takahashi;Hiroyuki Oguma;Akihisa Takeuchi;Masayuki Uesugi;Kentaro Uesugi

2023年06月, 一般社団法人日本複合材料学会, 論文賞　　　　　　　　　　　　　　　
放射光 X線ナノ CT を用いたその場引張・疲労試験による炭素繊維－エポキシ樹脂の界面はく離検出
勝谷 亮介;松尾 拓磨;髙橋 航圭;藤村 奈央;中村 孝

2022年06月, 日本複合材料学会, 林賞　　　　　　　　　　　　　　　
強化繊維の表面・界面を介した変形・強度評価手法の構築
高橋航圭

2019年05月, 日本接着学会, 進歩賞　　　　　　　　　　　　　　　
キャビティ膨張とフィブリル伸張に基づくはく離強度の粘着剤・基材厚さ依存性に関する考察
高橋 航圭

2017年04月, 日本機械学会, 日本機械学会奨励賞（研究）　　　　　　　　　　　　　　　
微細構造体の表面エネルギーに起因する吸着力・接着力の評価に関する研究
高橋 航圭

2015年11月, 日本機械学会材料力学部門, M&M若手シンポジウム2015 優秀講演表彰　　　　　　　　　　　　　　　
毛細管現象の吸着力による平板の変形過程
高橋 航圭

2014年03月, 日本機械学会材料力学部門, M&M 2013材料力学カンファレンス 優秀講演表彰　　　　　　　　　　　　　　　
濡れによる液架橋形成が及ぼす平板の変形評価
高橋 航圭

Quantitative analysis of interface crack propagation along a single carbon fiber under off-axis cyclic loading using nanoscopic three-dimensional imaging
Naoya Matsuda, Kosuke Takahashi
Composites Science and Technology, 2026年03月
研究論文（学術雑誌）

Adhesion testing of dysphagia diets for the quantitative evaluation of swallowing
Kosuke Takahashi, Ryo Yoshida, Kohei Ohie, Satomi Kumagai, Yuji Tasaka
Food Hydrocolloids, 2026年03月
研究論文（学術雑誌）

Enhancement of Strength and Durability in Single-Lap Joints using Thin Double-Sided Tape
Ashwani Kumar Devisharan, Xuan Ngoc Chau Ho, Kounosuke Shimamura, Kosuke Takahashi
2026年

Viscous dissipative energy density as a general adhesion characteristic of adhesive tape
Kosuke Takahashi, Masako Yamada, Tatsuya Sasaki, Takashi Nakamura
Soft Matter, Royal Society of Chemistry (RSC), 2025年07月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）, The adhesion energy (G_c) divided by the maximum elongation of the PSA layer (a_f), which is defined as the viscous dissipative energy density, and the strain rate has a linear relationship on a logarithmic scale, independent of the tape thickness.

Influence of irradiation with synchrotron radiation X-ray on Nano-Scale CT for carbon fibers and epoxy matrix
Kosuke Takahashi, Takuma Matsuo, Katsuma Wakabayashi, Akihisa Takeuchi, Masayuki Uesugi, Kentaro Uesugi, Takashi Nakamura
Composites Part A: Applied Science and Manufacturing, 198, 109060, 109060, Elsevier BV, 2025年05月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）, 30964622

Decreasing propagation rate of interfacial debonding between a single carbon fiber and epoxy matrix under cyclic loading
Kosuke Takahashi, Takuma Matsuo, Wataru Sato, Takashi Nakamura
Composites Science and Technology, 258, 2024年11月10日, ［査読有り］, ［筆頭著者, 責任著者］
研究論文（学術雑誌）

In situ analysis of three-dimensional microcrack propagation in cross-ply laminates using synchrotron radiation X-ray computed tomography
Kosuke Takahashi, Ryuto Higashiyama, Gaoge Xue, Takashi Nakamura
Composites Science and Technology, 258, 2024年11月10日, ［査読有り］, ［筆頭著者, 責任著者］
研究論文（学術雑誌）

セメントの空隙率空間分布が骨材混入による割裂引張強度の変化に及ぼす影響
Riki NAGAO, Kosuke TAKAHASHI, Kota OHYAMA, Masato TSUJINO
日本複合材料学会誌, 50, 5, 11, 18, 2024年09月15日, ［査読有り］, ［責任著者］, ［国内誌］
日本語, 研究論文（学術雑誌）

Toughened single-lap joints by composite bondline of adhesive and double-sided tape
Kosuke Takahashi, Zhantong Sun, Takuma Kikuzawa, Kounosuke Shimamura, Sourabh Jagrat, Nao Fujimura, Takashi Nakamura
Advanced Composite Materials, 1, 17, Informa UK Limited, 2023年11月20日, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）, 30964513

窒素環境におけるScanning Cyclic Pressを用いた純チタンの常温窒化
舩木 優大, 藤村 奈央, 中村 孝, 髙橋 航圭, 和島 達希
日本金属学会誌, 87, 11, 305, 308, Japan Institute of Metals, 2023年11月01日, ［査読有り］
日本語, 研究論文（学術雑誌）

Full-life growth behavior of a naturally initiated internal fatigue crack in beta titanium alloy via in situ synchrotron radiation multiscale tomography
Gaoge Xue, Takashi Nakamura, Nao Fujimura, Kosuke Takahashi, Hiroyuki Oguma, Akihisa Takeuchi, Masayuki Uesugi, Kentaro Uesugi
International Journal of Fatigue, 170, 107571, 107571, Elsevier BV, 2023年05月, ［査読有り］
研究論文（学術雑誌）

微小内部き裂の発生・進展挙動に基づくα+β型チタン合金の疲労寿命分布解析
森下 弘法, 中村 孝, 藤村 奈央, 髙橋 航圭
材料, 71, 12, 997, 1004, Society of Materials Science, Japan, 2022年12月15日, ［査読有り］
日本語, 研究論文（学術雑誌）

Generalized characteristics of peel tests independent of peel angle and tape thickness
Masako Yamada, Kosuke Takahashi, Nao Fujimura, Takashi Nakamura
Engineering Fracture Mechanics, 271, 2022年08月, ［査読有り］, ［責任著者］
研究論文（学術雑誌）

X-ray nanoimaging of a transversely embedded carbon fiber in epoxy matrix under static and cyclic loads
Kosuke Takahashi, Ryosuke Shoya, Takuma Matsuo, Wataru Sato, Takashi Nakamura, Akihisa Takeuchi, Masayuki Uesugi, Kentaro Uesugi
Scientific Reports, 12, 1, 2022年05月, ［査読有り］, ［筆頭著者, 責任著者］
研究論文（学術雑誌）

Initiation and propagation of small fatigue crack in beta titanium alloy observed through synchrotron radiation multiscale computed tomography
Gaoge Xue, Takashi Nakamura, Nao Fujimura, Kosuke Takahashi, Hiroyuki Oguma, Akihisa Takeuchi, Masayuki Uesugi, Kentaro Uesugi
Engineering Fracture Mechanics, 263, 108308, 108308, Elsevier BV, 2022年03月, ［査読有り］
研究論文（学術雑誌）

Detection of small internal fatigue cracks in Ti-6Al-4V via synchrotron radiation nanocomputed tomography
Gaoge Xue, Yuta Tomoda, Takashi Nakamura, Nao Fujimura, Kosuke Takahashi, Fumiyoshi Yoshinaka, Akihisa Takeuchi, Masayuki Uesugi, Kentaro Uesugi
Fatigue and Fracture of Engineering Materials and Structures, 2022年, ［査読有り］
研究論文（学術雑誌）

Sticking Effect of a Tackifier on the Fibrillation of Acrylic Pressure-Sensitive Adhesives
Takahashi, K., Yanai, F., Inaba, K., Kishimoto, K., Kozone, Y., Sugizaki, T.
Langmuir, 37, 39, 11457, 11464, American Chemical Society ({ACS}), 2021年10月05日, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

放射光X線ナノCTを用いたその場引張・疲労試験による炭素繊維–エポキシ樹脂の界面はく離検出
Ryosuke SHOYA, Takuma MATSUO, Kosuke TAKAHASHI, Nao FUJIMURA, Takashi NAKAMURA
日本複合材料学会誌, 47, 5, 186, 193, 2021年09月15日, ［査読有り］, ［責任著者］, ［国内誌］
日本語, 研究論文（学術雑誌）

Initiation and Propagation Processes of Internal Fatigue Cracks in β Titanium Alloy Based on Fractographic Analysis
Gaoge Xue, Takashi Nakamura, Nao Fujimura, Kosuke Takahashi, Hiroyuki Oguma
Applied Sciences, 11, 1, 131, 131, 2020年12月25日, ［査読有り］
英語, 研究論文（学術雑誌）

Laminate design for a tapered FRP structure with ply drop-off based on yielding of resin pockets
Sae Obata, Kosuke Takahashi, Kazuaki Inaba
Composite Structures, 253, 112787, 112787, Elsevier {BV}, 2020年12月, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）

Scaling effect on the detachment of pressure-sensitive adhesives through fibrillation characterized by a probe-tack test
Takahashi, K., Oda, R., Inaba, K., Kishimoto, K.
Soft Matter, 16, 28, 6493, 6500, Royal Society of Chemistry ({RSC}), 2020年06月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

Surface modification of machine-finished magnesium alloy AZ31 using a scanning cyclic press
Nao Fujimura, Koyo Ooga, Kosuke Takahashi, Takashi Nakamura, Tatsuki Wajima
MECHANICAL ENGINEERING JOURNAL, 7, 4, 2020年, ［査読有り］
英語, 研究論文（学術雑誌）

Bending Deformation of Multiple Aligned Plates Toward Coalescence Induced by Capillarity
Takahashi, K., Matsuo, T., Inaba, K., Kishimoto, K.
Journal of Microelectromechanical Systems, 28, 4, 685, 694, Institute of Electrical and Electronics Engineers ({IEEE}), 2019年08月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

継手部加工によるFe-Alレーザー溶接継手の疲労強度決定因子の検討
Kosuke TAKAHASHI, Hiroshi FUKAZAWA, Kouta WAKUI, Farid TRIAWAN, Kazuaki INABA, Kikuo KISHIMOTO, Toru HASHIMURA
Transactions of the JSME (in Japanese), 84, 865, 18, 00137-18-00137, 一般社団法人 日本機械学会, 2018年09月, ［査読有り］, ［筆頭著者, 責任著者］, ［国内誌］
日本語, 研究論文（学術雑誌）, <p>Weld-joint has been atracting attention to assemble structures of dissimilar metals, particularly in automobile industry. However, the application of weld-joint to steel and aluminum plates is still limited due to uncertainty of the fatigue strength. Fatigue strength of weld-joint is rather complicated to evaluate because both effects of stress concentration at the edge and formation of intermetallic compounds along the interface should be considered carefully. This study focused on finding the key factor that determines the fatigue strength of steel-aluminum brazing joint by considering the variation of strength along interface. The welded part of single lap joint was partially removed by a wire-cut electric discharge machine to investigate the influence of length and location of interface on fatigue strength. When the applied load was relatively low it was found that the numbers of cycles to failure were found to be similar, even though the lengths of interface were different due to partial removal. Furthermore, observation on the fracture surface indicated that early stage of crack propagation showed similar topography regardless of the partial removal of weld part. These results clarified that the number of cycles to failure was mainly consumed at the early stage. Finite element analysis was then conducted to investigate the stress component affecting the fatigue strength. As a result, principal stresses were maximum at the fracture initiation site in all the specimens. Therefore, we concluded that fatigue life of weld-joint is dominant in the early stage of crack propagation, which is characterized by the principal stress.</p>

オーステナイト系ステンレス鋼の低サイクル疲労における表面性状の変化機構
Nao FUJIMURA, Yuto NISHIZUKA, Kosuke TAKAHASHI, Takashi NAKAMURA
Transactions of the JSME (in Japanese), 84, 864, 18, 00206-18-00206, 一般社団法人 日本機械学会, 2018年, ［査読有り］, ［国内誌］
日本語, 研究論文（学術雑誌）, <p>To quantitatively investigate the cause of the changes in arithmetic mean roughness <i>R_a</i> of austenitic stainless steel under low-cycle fatigue loading, precise observation focusing on slip bands was conducted on SUS316NG. During the loading, the specimen's surface topography was regularly measured using a laser microscope. The topography was then characterized by frequency analysis to identify the surface reliefs due to persistent slip bands (PSBs), and their heights were measured. The heights increased with the usage factor (<i>UF</i>). The amount of the increase with respect to <i>UF</i> increased with the strain range. These tendencies are similar to those for <i>R_a</i>. A comparison between <i>R_a</i> and the heights of surface reliefs caused by PSBs showed that the values were strongly correlated. The number of PSBs formed on the surface was estimated from the area ratio of PSBs. The area ratio increased with <i>UF</i>, which is similar to the relationship for <i>R_a</i>. A comparison between <i>R_a</i> and the area ratio showed that these values were also strongly correlated. The product of the height due to PSBs and the area ratio was calculated and it was compared with <i>R_a</i>. As a result, the product was in good agreement with <i>R_a</i>. Consequently, the surface texture parameter <i>R_a</i> represent both the change in the height and the number of surface reliefs due to PSBs.</p>

Cavitation damage of epoxy resin subjected to uniaxial tensile loading
HIBI Masaharu, TRIAWAN Farid, INABA Kazuaki, TAKAHASHI Kosuke, KISHIMOTO Kikuo, HAYABUSA Keisuke, NAKAMOTO Hiroaki
Mechanical Engineering Journal, 5, 1, 17, 00151-17-00151, 一般社団法人 日本機械学会, 2018年, ［査読有り］
英語, 研究論文（学術雑誌）, <p>In turbomachinery, such as turbine, pump, and valve, components damage caused by collapsing cavitation bubbles has been a critical issue that needs a proper solution. For this reason, investigation on the cavitation erosion behavior of materials as well as the life prediction techniques has been extensively conducted. Moreover, a number of repairing techniques, such as by a surface coating of polymeric materials, has been established. However, in real operation, cavitation is actually not the only load acquired by the components. Other external loads, such as centrifugal force and hydraulic pressure, may also affect the generation of damage. Therefore, its effect on the lifetime needs to be considered carefully. In this paper, the behavior of cavitation damage of epoxy resin specimens subjected to uniaxial tensile loading is reported. A self-developed testing device was used to conduct a cavitation test based on ASTM G32 while at the same time exerting a constant uniaxial tensile load to the specimen. Using this device, various levels of tensile stress effect on the cavitation damage was examined. As a result, besides erosion damage, we revealed that the specimens demonstrated fracture when a certain tensile load was applied. Furthermore, as the tensile load was increased, the time to fracture was shortened significantly, indicating the pronounced effect of tensile stress on the damage formation. The crack growth mechanism was then analyzed by fractography. The result indicated that the crack propagation under a mixed condition of cavitation and tensile loads was most likely driven by the combination of creep deformation and fatigue-like crack growth. Finally, a mathematical relationship between tensile stress and cavitation damage life was proposed. The relationship is important to enhancing the existing theory of cavitation damage evaluation in e.g. turbomachinery application.</p>

Scanning Cyclic Pressによるマグネシウム合金AZ31の表面改質と疲労特性改善効果
藤村 奈央, 中村 孝, 髙橋 航圭, 和島 達希
材料試験, 66, 12, 906, 912, 公益社団法人 日本材料学会, 2017年12月01日, ［査読有り］
日本語, 研究論文（学術雑誌）

Dynamics of Wave Propagation Across Solid–Fluid Movable Interface in Fluid–Structure Interaction
Tomohisa Kojima, Kazuaki Inaba, Kosuke Takahashi, Farid Triawan, Kikuo Kishimoto
Journal of Pressure Vessel Technology, 139, 3, 031308, 2017年06月, ［査読有り］
英語, 研究論文（学術雑誌）

Evaluation of interfacial strength between fiber and matrix based on cohesive zone modeling
Bentang Arief Budiman, Kosuke Takahashi, Kazuaki Inaba, Kikuo Kishimoto
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING, 90, 211, 217, 2016年11月, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）

Characterization of Tack Strength Based on Cavity-Growth Criterion
Kosuke Takahashi, Yuichiro Yamagata, Kazuaki Inaba, Kikuo Kishimoto, Shiori Tomioka, Toshio Sugizaki
LANGMUIR, 32, 14, 3525, 3531, 2016年04月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

ペレットを有する円筒容器の衝撃挙動に関する研究
森重直樹, 森重直樹, 高橋航圭, 因幡和晃, 岸本喜久雄
日本機械学会論文集(Web), 82, 841, ROMBUNNO.16‐00194(J‐STAGE), 00194-16-00194, 一般社団法人 日本機械学会, 2016年, ［査読有り］
日本語, 研究論文（学術雑誌）,

The dynamic buckling tests using cylindrical tubes with and without internal pellets were carried out to investigate the impact behavior. Various materials of cylindrical tubes and pellets were used to examine the buckling mode and the maximum loads at several impact velocities. In the case of low Young's modulus and low yield strength pellets, the influence of pellets was small because of the small load share of pellets, so the "W" shape of deformation shapes and the maximum impact loads were almost the same of those of empty tubes. On the other hand, the tubes with high Young's modulus and high yield strength pellets indicated different behaviors compared to the empty tubes because of the large load share of pellets. At low impact velocity, pellets with high yield strength caused the strengthening effect and increased the lateral stiffness for tubes. As a result, the pellets led to increase of impact load, decrease of deformation and change of buckling mode to the "S" shape. At high velocity, the strengthening effect of pellets made the tubes stiffer, but led to fracture by the constraint effect of pellets on plastic deformation. The deformation of tubes was compared to Euler's equation, and it was confirmed that the Euler's equation could be applied at the low impact velocity. However, it was not effective for the high velocity impact because of local deformation at the impact side. FEM analyses will be conducted to clarify the deformation shape, maximum load and the mechanism of fracture at high impact velocity as a further study.

Wetting-induced attraction of thin plates due to capillary flow
Kosuke TAKAHASHI, Takahiro MATSUO, Masakazu FURUTA, Shuzo OSHIMA, Kazuaki INABA, Kikuo KISHIMOTO
Mechanical Engineering Letters, 2, 0, 16, 00227-16-00227, Japan Society of Mechanical Engineers, 2016年, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）,

Wetting-induced attraction are widely observed in microstructures where liquid flows along solid surfaces. Unexpected bending or collapse occurs if wetting-induced forces are neglected in the structural design, such as high aspect ratio pillars in the process of wet-etching. In this study, a simple experiment is designed to capture the evolving deformation of a cantilever beam due to capillary flow. A pair of polymer plates fixed at one end with a small gap is submerged into liquid, so that capillary rise between the plates and their attraction can be simultaneously observed. The plate dimension is sub-millimeter scale, which is rather large in observation of capillarity, in order to clearly capture deformation process of the plates until their contacts. Different types of liquids are prepared to investigate the influence of wettability, surface tension, and viscosity. Velocity of capillary flow is also considered by changing submergence rate of the plate. The experimental results of plate deflection are compared to analytical estimation obtained from an equation of motion for capillary rise and an equilibrium between capillary attraction and elastic force of plate. This estimation corresponded well with experimental results regardless of liquid types. In addition, the relationship between plate deflection and material constants is derived in a non-dimensional form. Therefore, plate deformation due to wetting-induced attraction, considering velocity of capillary flow, became predictable only from dimension of plates and material constants.

粘着剤の非線形粘弾性を考慮したはく離強度評価
高橋 航圭, 熊谷, 理 勝山, 優一郎, 因幡, 和晃, 岸本, 喜久雄, 山田, 幹典谷中, 雅顕
日本機械学会論文集, 82, 833, The Japan Society of Mechanical Engineers, 2016年, ［査読有り］, ［筆頭著者, 責任著者］
日本語, 研究論文（学術雑誌）, Peel test is widely used to evaluate interfacial strength of adhesive tape. The interface strength is usually obtained by subtracting energy consumed for plastic deformation of substrate film from external work for peeling. Deformation of substrate results from interface strength generated in adhesive layer, whose mechanical property is regarded as elastic when substrate is thick enough. It is also convenient to calculate deformation of substrate with assuming elastic behavior of adhesive layer. However, substrates thinner than 100 μm may be affected by viscoelastic property of adhesive layer since thickness of adhesive layer is no longer negligible. It is indispensable to investigate the influence of viscoelastic behavior of adhesive layer on evaluating interface strength of particularly thin adhesive film. In this study, 90° peel test was conducted and the interface strength was evaluated by modifying conventional elastic model to consider viscoelastic behavior of adhesive layer. Stress in adhesive layer caused from displacement of substrate is a function of strain and strain rate, and the corresponding deformation of substrate was computed by finite element method. The shape of substrate deformation was compared with one obtained from conventional elastic model in terms of thickness of substrate and peel speed. The interface strength was also obtained from directly observing peel shape using high speed camera to validate the proposed model. As a result, it was found that the substrate shapes were similar regardless of models when substrate was thick, but proposed model more accurately reflected the influence of peel speed in the thin substrate.

Instant electrode fabrication on carbon-fiber-reinforced plastic structures using metal nano-ink via flash light sintering for smart sensing
Kosuke Takahashi, Kensuke Namiki, Takahiro Fujimura, Eun-Beom Jeon, Hak-Sung Kim
COMPOSITES PART B-ENGINEERING, 76, 167, 173, 2015年07月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

A new method of evaluating interfacial properties of a fiber/matrix composite
Bentang Arief Budiman, Kosuke Takahashi, Kazuaki Inaba, Kikuo Kishimoto
JOURNAL OF COMPOSITE MATERIALS, 49, 4, 465, 475, 2015年02月, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）

An investigation of contact resistance between carbon fiber/epoxy composite laminate and printed silver electrode for damage monitoring
Eun-Beom Jeon, Takahiro Fujimura, Kosuke Takahashi, Hak-Sung Kim
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING, 66, 193, 200, 2014年11月, ［査読有り］
英語, 研究論文（学術雑誌）

Interaction of Serum Proteins with Hemodialysis Membrane: Comparison with De-adhesion Process of AFM Probe from Adhesive Tapes
Rehana Afrin, Atsushi Ikai, Kosuke Takahashi, Kazuaki Inaba, Kikuo Kishimoto
MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 603, 1, 157, 164, 2014年11月, ［査読有り］
英語, 研究論文（学術雑誌）

Evaluation of Contact Resistance between Carbon Fiber/Epoxy Composite Laminate and Printed Silver Electrode for Damage Monitoring
Eun-Beom Jeon, Kosuke Takahashi, Hak-Sung Kim
Journal of the Korean Society for Nondestructive Testing, 34, 5, 377, 383, The Korean Society of Nondestructive Testing, 2014年10月30日, ［査読有り］
朝鮮語, 研究論文（学術雑誌）

Supercritical CO2 generator using bubble collapse by water hammer
Hiroyuki Ushifusa, Kazuaki Inaba, Kosuke Takahashi, Kikuo Kishimoto
JOURNAL OF SUPERCRITICAL FLUIDS, 94, 174, 181, 2014年10月, ［査読有り］
英語, 研究論文（学術雑誌）

Transient phenomena in wave propagation around a large suspended particle in a water-filled tube
Tatsuro Hori, Kazuaki Inaba, Kosuke Takahashi, Kikuo Kishimoto
Applied Mechanics and Materials, 566, 431, 436, Trans Tech Publications Ltd, 2014年, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）

Filtering effects of periodic structure in water hammer
Minoru Nagai, Kazuaki Inaba, Kosuke Takahashi, Kikuo Kishimoto
Applied Mechanics and Materials, 566, 50, 55, Trans Tech Publications Ltd, 2014年, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）

機械・構造物補修用コーティング材料の耐キャビテーション評価
高橋航圭, 新井大輔, 因幡和晃
ターボ機械, 42, 12, 767, 776, 日本工業出版, 2014年, ［査読有り］, ［筆頭著者, 責任著者］
日本語, Structural repair by polymer coating has been recently attracted attention to pumps in water plants because of its simplicity.The performance of coating material is simply evaluated by cavitation resistance, but it should be considered under loadingcondition for application to existing structures. In this study, damage of coating material due to cavitation is observedwith various loading conditions. Epoxy resin is selected as coating material on aluminum base. First, tensile and shear testsof the coating material is conducted with different way of coating angles to obtain fracture stresses. Second, a conventionalcavitation erosion test is modified using a tensile jig developed to conduct a tension-cavitation test. As a result, the tensioncavitationtest resulted in much severer damage in short time than conventional cavitation erosion test even though the stresson the coating material is more than 10 times smaller than the fracture stresses.

Evaluation of capillary-induced deformation of thin plates due to liquid column formation
Kosuke Takahashi, Seiji Sugita, Shuzo Oshima, Kazuaki Inaba, Kikuo Kishimoto
Applied Physics Letters, 103, 4, 043113, AIP Publishing, 2013年07月22日, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

A Modeling of Cerebral Blood Flow Changes due to Head Motion for fNIRS
Takahashi, K., Tanaka, T., Nara, H., Kaneko, S., Inoue, M., Shimizu, S., Kojima, S.
International Journal of Optomechatronics, 7, 2, 2013年
研究論文（学術雑誌）

Tack performance of pressure-sensitive adhesive tapes under tensile loading
Kosuke Takahashi, Masashi Shimizu, Kazuaki Inaba, Kikuo Kishimoto, Yoichi Inao, Toshio Sugizaki
International Journal of Adhesion and Adhesives, 45, 90, 97, Elsevier, 2013年, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

Towards practical application of electrical resistance change measurement for damage monitoring using an addressable conducting network
Kosuke Takahashi, H. Thomas Hahn
STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL, 11, 3, 367, 377, 2012年05月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

Autonomic thermal management of graphite fiber/epoxy composite structures using an addressable conducting network
Kosuke Takahashi, H. Thomas Hahn
COMPOSITES PART B-ENGINEERING, 43, 3, 833, 840, 2012年04月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

Investigation of temperature dependency of electrical resistance changes for structural management of graphite/polymer composite
Kosuke Takahashi, H. Thomas Hahn
JOURNAL OF COMPOSITE MATERIALS, 45, 25, 2603, 2611, 2011年12月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

Multiple healing effect of thermally activated self-healing composites based on Diels-Alder reaction
Jong Se Park, Thomas Darlington, Anthony F. Starr, Kosuke Takahashi, Joseph Riendeau, H. Thomas Hahn
COMPOSITES SCIENCE AND TECHNOLOGY, 70, 15, 2154, 2159, 2010年12月, ［査読有り］
英語, 研究論文（学術雑誌）

An addressable conducting network for autonomic structural health management of composite structures
Kosuke Takahashi, Jong Se Park, H. Thomas Hahn
SMART MATERIALS & STRUCTURES, 19, 10, 105023, 2010年10月, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）

Simultaneous Measurement of Multiple Electrical Resistance Changes with Strain of CFRP
TAKAHASHI Kosuke, TODOROKI Akira, MATSUZAKI Ryosuke
Journal of Solid Mechanics and Materials Engineering, 4, 4, 557, 567, The Japan Society of Mechanical Engineers, 2010年, ［査読有り］, ［筆頭著者］
英語, Strain monitoring of CFRP structure by measuring electrical resistance change has attracted attention over the years. High electrical conductivity of carbon fibers enables to measure the strain by making electrodes on the structure's surface and using bridge circuit as conventional strain gauge. Electrical resistance change method, however, is difficult to specify the gauge length because electric current is applied directly to the structure, and the current path depends on the stacking sequences, fiber volume fraction, and electrode's location. It is also difficult to measure the electrical resistance changes at different parts simultaneously because the outputs may interfere with each other due to overlapping of current paths inside the structure. In this study, three electrodes are connected to each bridge circuit to prevent electrical interference when the electrical resistance changes are measured simultaneously, whereas electrical resistance measurements normally use two electrodes. The proposed method puts ground electrodes every other so that current path could be limited between the ground electrodes. Only the strain between ground electrodes affects the electrical resistance output, and it makes simultaneous measurements at different position possible.

Electrical Resistance Change Measurement with Elevated Temperature due to Joule Heating for the Detection of Delamination in Graphite/Epoxy Composites
Takahashi Kosuke, Todoroki Akira, Matsuzaki Ryosuke
Journal of Environment and Engineering, 5, 1, 15, 26, The Japan Society of Mechanical Engineers, 2010年, ［査読有り］, ［筆頭著者］
英語, Delamination cracks in a graphite/epoxy composite change the thermal expansion properties in the damaged regions. We detect this change by measuring the electrical resistance in the affected areas while heating. The proposed damage detection method is effective even when a damaged electrode is used, in contrast to the traditional method, which requires highly reliable electrodes to prevent an increase of the inherent electrical resistance. The proposed damage detection method is thus feasible for a variety of environments that might cause the degradation of the electrode. Heating of the composite is performed by Joule heating of the graphite fibers rather than general heating using an outside heat source. Graphite fibers, due to their high electrical conductivity, are used not only as the damage sensor but also as the heat source. The influences of delamination and electrode defects on a heated cross-ply beam are examined by simulation. The electrical resistance change after Joule heating is also experimentally measured. As a result, we proved that delamination detection is possible even with a damaged electrode.

抵抗温度特性変化を利用した CFRP 平板の統計的層間はく離検出
鈴木良郎, 轟章, 高橋航圭, 水谷義弘, 松崎亮介
日本機械学會論文集. A 編, 76, 767, 961, 967, 一般社団法人日本機械学会, 2010年, ［査読有り］
日本語, 研究論文（学術雑誌）

Towards Development of a Self-Healing Composite using a Mendable Polymer and Resistive Heating
Jong Se Park, Kosuke Takahashi, Zhanhu Guo, Ying Wang, Ed Bolanos, Christine Hamann-Schaffner, Erin Murphy, Fred Wudl, H. Thomas Hahn
JOURNAL OF COMPOSITE MATERIALS, 42, 26, 2869, 2881, 2008年12月, ［査読有り］
英語, 研究論文（学術雑誌）

Time-synchronized wireless strain and damage measurements at multiple locations in CFRP laminate using oscillating frequency changes and spectral analysis
Ryosuke Matsuzaki, Akira Todoroki, Kosuke Takahashi
SMART MATERIALS & STRUCTURES, 17, 5, 055001, 2008年10月, ［査読有り］
英語, 研究論文（学術雑誌）

CFRP のひずみに伴う電気抵抗変化の多点同時測定
高橋航圭, 轟章, 松崎亮介
日本機械学会論文集 A 編, 74, 748, 1573, 1579, The Japan Society of Mechanical Engineers, 2008年, ［査読有り］, ［筆頭著者］
日本語, Strain monitoring of CFRP structure by measuring electrical resistance change has attracted attention over the years. High electrical conductivity of carbon fibers enables to measure the strain by making electrodes on the structure's surface and using bridge circuit as conventional strain gauge. Electrical resistance change method, however, is difficult to specify the gauge length because electric current is applied directly to the structure, and the current path depends on the stacking sequences, fiber volume fraction, and electrode's location. It is also difficult to measure the electrical resistance changes at different parts simultaneously because the outputs may interfere with each other due to overlapping of current paths inside the structure. In this study, three electrodes are connected to each bridge circuit to prevent electrical interference when the electrical resistance changes are measured simultaneously, whereas electrical resistance measurements normally use two electrodes. The proposed method puts ground electrodes every other so that current path could be limited between the ground electrodes. Only the strain between ground electrodes affects the electrical resistance output, and it makes simultaneous measurements at different position possible.

ジュール発熱による電気抵抗変化を利用した CFRP 構造物の層間はく離検知
高橋航圭, 轟章, 松崎亮介
日本機械学会論文集 A 編, 74, 748, 1565, 1572, The Japan Society of Mechanical Engineers, 2008年, ［査読有り］, ［筆頭著者］
日本語, Delamination of CFRP structure is detected by means of electrical resistance change due to Joule heating in the present study. A CFRP beam is heated up by applying electric current through electrodes mounted on the surface. When the CFRP beam is heated up, the thermal expansion at the part with a delamination is different from that at the undamaged part, and the difference of the thermal expansion affects the electrical resistance change with elevated temperature because CFRP has piezoelectricity. The electrical resistance changes between the electrodes are measured using bridge circuits just like using conventional strain gauge. In addition, the effect of electrode's damage on the electrical resistance change is also considered because the quality of the electrode is important to identify delamination. Electrical resistance change due to Joule heating is measured using a cross-plied CFRP beam with a delamination and electrode's damage, and as a result, delamination detection is even possible with a damaged electrode.

Statistical damage detection of laminated CFRP beam using electrical resistance change method
Kosuke Takahashi, Akira Todoroki, Yoshinobu Shimamura, Atsushi Iwasaki
PROGRESSES IN FRACTURE AND STRENGTH OF MATERIALS AND STRUCTURES, 1-4, 353-358, 1330, +, 2007年, ［査読有り］, ［筆頭著者］
英語, 研究論文（国際会議プロシーディングス）

発振周波数変化とスペクトル解析を用いたCFRP積層板のひずみ・損傷複数点同期無線測定
松崎 亮介, 轟 章, 高橋 航圭
日本機械学会論文集. A編 = Transactions of the Japan Society of Mechanical Engineers. A, 73, 724, 1904, 1911, 一般社団法人日本機械学会, 2006年12月25日, ［査読有り］
日本語, Wireless health monitoring for CFRP structures reduces the cost and time of inspection and it can be useful for continuous monitoring. In the previous study, we presented a wireless sensor for detection of internal delamination in a CFRP laminate. The method utilizes a simple electric resistance change in CFRP, thus it monitors delamination at only one location. For monitoring of large-scale structures, however, many sensors have to be distributed to cover the structure. Major problem for using many sensors is the time synchronization among sensors. To overcome the problem and enable to monitor strain/damage at multiple locations with time synchronization, we develop wireless strain/damage sensor which simply consists of a bridge circuit, voltage controlled oscillator and amplifiers. Since the sensor does not need procedures of AD conversion or memory storing, the time delay does not take place. Each sensor has original basic frequency which changes due to the electric resistance, and the frequencies from multiple sensors are transmitted to a receiver. Using short-time maximum entropy method, received wave is converted to multiple electric resistance data at one time. The proposed method is applied to CFRP laminates and oscillating frequencies are measured in real-time. As the result, the system successfully measures the applied strain and detects fiber breakage at multiple locations in CFRP laminate with time synchronization.

振動圧縮負荷による純チタン表層の常温窒化現象とその要因　　　　　　　　　　　　　　　
舩木優大, 中村孝, 髙橋航圭, 和島達希, 熱処理, 65, 2, 75, 78, 2025年05月, ［査読有り］, ［招待有り］
日本語, 記事・総説・解説・論説等（学術雑誌）

チタン合金のギガサイクル疲労における微小内部き裂の非破壊観察
中村 孝, 吉中 奎貴, 薛 高格, 藤村 奈央, 髙橋 航圭, まてりあ, 63, 11, 770, 775, 2024年11月01日
Japan Institute of Metals

複合材料の超長寿命化に向けたナノ界面の疲労き裂検出
高橋航圭, 材料, 73, 8, 663, 668, 2024年08月, ［招待有り］, ［筆頭著者, 責任著者］
日本語, 記事・総説・解説・論説等（学術雑誌）, 30964622

海外で博士進学
髙橋 航圭, 材料, 72, 2, 150, 2023年02月15日
公益社団法人 日本材料学会, 日本語

材料力学的アプローチによるはく離強度の粘着剤厚さ・基材厚さ依存性の評価
高橋航圭, 日本接着学会誌, 46, 4, 125, 132, 2020年, ［招待有り］, ［筆頭著者, 責任著者］
日本語, 記事・総説・解説・論説等（学術雑誌）

ぬれが及ぼす微細構造体における吸着力・接着力の評価と課題
高橋航圭, 因幡和晃, 岸本喜久雄, 日本接着学会誌, 50, 7, 235, 242, 2014年07月, ［招待有り］, ［筆頭著者, 責任著者］
一般社団法人 日本接着学会, 日本語, 記事・総説・解説・論説等（学術雑誌）

スマートストラクチャ(6)セルフヒーリングコンポジット
高橋 航圭, Hahn H. Thomas, 強化プラスチックス, 55, 9, 340, 345, 2009年09月, ［招待有り］, ［筆頭著者, 責任著者］
強化プラスチック協会, 日本語, 記事・総説・解説・論説等（学術雑誌）

接着・接合の支配要因と最適化技術
18 粘着テープのバルク特性に着目したはく離強度評価
S&T出版, 2021年02月, 9784907002848, xiii, 271p, 図版[4]p, 日本語, ［分担執筆］

「食べやすさ」の定量化へ向けた粘着性能評価試験の応用　　　　　　　　　　　　　　　
吉田稜生, 中村孝, 高橋航圭
日本接着学会年次大会講演要旨集(CD-ROM), 2024年
2024年 - 2024年

Scanning cyclic pressによる表面改質を施したマグネシウム合金の疲労特性　　　　　　　　　　　　　　　
藤村奈央, 高橋航圭, 中村孝, 和島達希
疲労シンポジウム講演論文集, 2024年
2024年 - 2024年

βチタン合金における内部疲労き裂進展特性　　　　　　　　　　　　　　　
XUE Gaoge, 藤村奈央, 高橋航圭, 中村孝
疲労シンポジウム講演論文集, 2024年
2024年 - 2024年

(α+β)Ti-6Al-4Vにおける内部疲労き裂の繰返し圧縮負荷による凝着挙動　　　　　　　　　　　　　　　
舩木優大, 増谷幸香, XUE Gaoge, 高橋航圭, 藤村奈央, 中村孝
疲労シンポジウム講演論文集, 2024年
2024年 - 2024年

析出硬化ステンレス鋼SUS630の表面および内部起点型微小疲労き裂進展特性　　　　　　　　　　　　　　　
上野竜史, XUE Gaoge, 舩木優大, 高橋航圭, 藤村奈央, 中村孝
疲労シンポジウム講演論文集, 2024年
2024年 - 2024年

析出硬化ステンレス鋼SUS630における内部微小疲労き裂の発生・進展挙動　　　　　　　　　　　　　　　
中村孝, 五十嵐元, 藤村奈央, 高橋航圭
日本材料学会学術講演会講演論文集(CD-ROM), 2024年
2024年 - 2024年

Scanning Cyclic Pressを用いたマグネシウム合金の表面改質に及ぼす負荷繰返し数の影響
阿部 すずか, 藤村 奈央, 大賀 向陽, 髙橋 航圭, 中村 孝, 和島 達希
年次大会, 2020年, 一般社団法人 日本機械学会, 日本語
2020年 - 2020年, A new surface modification technique, scanning cyclic press (SCP), was developed. SCP scans a metal surface with a vibrating indenter and refines the surface layer using cyclic compressive loading. This study applied SCP to the surface of magnesium alloy AZ31 under number of cyclic loading of 3.2×10⁵ and 8.0×10⁶ cycles to investigate the effect on surface structure. After applying SCP, the cross sections of specimens were observed by electron back scattering diffraction (EBSD) using SEM. As a result, a fine structure around 1－10 μm in grain size and a twin were formed in the surface layer of both specimens. The depth of these structures from the surface remained unchanged regardless of the number of cyclic loading. However, the surface structure under 8.0×10⁶ cycles was finer than that under 3.2×10⁵ cycles. This is likely caused by the increase of accumulated plastic strain during SCP process.

雰囲気制御scanning cyclic pressによる純チタンの常温窒化プロセスに関する検討
福田 哲也, 上遠野 寛, 藤村 奈央, 髙橋 航圭, 中村 孝, 和島 達希
年次大会, 2020年, 一般社団法人 日本機械学会, 日本語
2020年 - 2020年, A new surface modification technique, scanning cyclic press (SCP), was applied to commercially pure titanium (CP-Ti) in a nitrogen atmosphere at room temperature. During the SCP process, a vibrating indenter reciprocally scanned the specimen’s surface to apply cyclic low compressive load. In this study, a possibility of a room-temperature-nitriding technique using SCP was investigated. Before and after SCP, the surface and the cross-section of the specimens were observed using a laser microscope and scanning ion microscope (SIM), respectively. Then, elemental and composition analyses were conducted by using EPMA and XRD. As a result, a pale golden color, which is known as a characteristic of titanium nitride coating, appeared at the surface of SCP-treated specimen. The SIM observation of the cross-section showed that a nanocrystalline structure was created in the surface layer, and the nitrogen element was detected in the same layer. The XRD analysis showed a strong possibility to form titanium nitride at the surface of SCP-treated specimen. These results suggested that nitrogen element surrounding the specimen diffused into the microstructure beneath the surface and likely created titanium nitride during SCP even at room temperature.

マルチスケール解析によるモルタル材料の損傷シミュレーション
大山 航汰, 高橋 航圭, 藤村 奈央, 中村 孝
年次大会, 2020年, 一般社団法人 日本機械学会, 日本語
2020年 - 2020年, In this study, multi-scale analysis was carried out by designing a porous cement paste model, and a mortar model using glass spheres as fine aggregates. The tensile simulation of porous cement paste model was conducted by RVE model that reflects the distribution of pore size in a cement specimen. It was shown that the elastic modulus and strength of cement have a linear relationship with porosity. The finite element model of cylindrical samples was then created to simulate the splitting tensile test. For the cylindrical mortar model, spatial variation of the physical properties due to the porosity distribution in cement was reflected. When cement had a distribution of physical properties, the strength of the cement model was similar to that of mortar model as it was observed from the experiment, whereas the strength of the cement model was higher by 20 % if uniform physical properties were used for cement matrix. It was confirmed that our simulation well corresponded to the experimental result of at the ages of 28 days. In addition, the decrease in the strength, which would be expected for further aging mortar, can be also modeled by the porous layer at glass-cement interface, representing the Interfacial Transition Zone.

放射光顕微CTによる高強度金属内部の高分解能非破壊観察
今 佑宇真, 中村 孝, 藤村 奈央, 吉中 奎貴, 髙橋 航圭, 竹内 晃久, 上椙 真之, 上杉 健太朗
M&M材料力学カンファレンス, 2019年, 一般社団法人 日本機械学会, 日本語
2019年 - 2019年, To investigate the initiation and propagation processes of internal fatigue crack in high strength metallic materials, high resolution and non-destructive observation technique was proposed. The opening and closing behaviors of fatigue cracks in Ti-6Al-4V, and the non-metallic inclusions in SNCM439, which are regarded as a potential crack initiation site, were observed by synchrotron radiation CT (SR-CT) at SPring-8. To ensure a sufficient X ray transmission, fatigue specimens with a small diameter were designed, and a tensile loading jig was newly developed to measure the CTOD during SR-CT. In Ti-6Al-4V, micro CT and nano CT with a resolution around 1 μm and 200 nm, respectively, were used to observe internal cracks. As a result, it was clarified that surface cracks and internal cracks showed different behaviors. The crack tip of surface cracks had a sharp shape and the CTOD was changed by the tensile load. On the other hand, the shape of crack tips of internal cracks was blunted, and the tensile load did not affect CTOD. This crack blunting was explained by the vacuum-like environment around the internal crack. In SNCM439, small non-metallic inclusions with the size around 8 μm in diameter were clearly observed. Accordingly, it is expected that we can observe the initiation and propagation of internal cracks in high strength steel by repeating fatigue tests and SR-CT alternately.

真空環境下におけるき裂進展速度に基づく内部き裂の疲労寿命推定
ソラブ クマール モディ, メヘンディラッタ パラス, 塚越 拓摩, 中村 孝, 藤村 奈央, 髙橋 航圭
M&M材料力学カンファレンス, 2019年, 一般社団法人 日本機械学会, 日本語
2019年 - 2019年, In recent years, it has been revealed that in high strength steel, fracture occurs from non-metallic inclusions inside of the material in the very high cycle region. However, because of the difficulty in directly observing the internal fatigue process, its mechanism is still unknown. Subsequently efforts are being made for better understanding of fatigue crack initiation and propagation. In this study, we have tried to estimate life in this subsurface fatigue region using crack growth rates measured in a vacuum environment and compare it with actual life found out in subsurface fractures in fatigue test to better understand fatigue crack properties.

表面改質技術Scanning Cyclic Pressによる低炭素鋼S25Cの疲労特性改善効果
丹野 椋子, 藤村 奈央, 中村 孝, 髙橋 航圭
M&M材料力学カンファレンス, 2019年, 一般社団法人 日本機械学会, 日本語
2019年 - 2019年, In this study, we applied a new surface modification technique, scanning cyclic press (SCP) to machined specimens of low carbon steel S25C. In the SCP process, a vibrating indenter scans the metal surface and cyclically applies a variable low compressive load to modify the microstructure at the surface. During applying the SCP, the processing parameters, such as the scanning speed, the amount of compressive load and the number of cyclic loading, were changed to investigate the effects on the microstructure and the fatigue property. After applying the SCP, the surface roughness of specimens became smaller than that before. To clarify the changes in the microstructure beneath the surface of the SCP-treated specimens, the cross-section was created using focused ion beam technique. Scanning ion microscopic observations showed the microstructure refinement at the surface layer. The microstructure refinement was promoted with increasing the scanning speed, and the surface hardness also increased. Additionally, at the higher compressive load and the larger number of cyclic loading, finer microstructure was observed at the surface layer above the modified microstructure. This result suggested that the microstructure refinement is promoted by increasing the amount and the number of compressive loading. Fatigue test results showed that the fatigue lives of the SCP-treated specimens were 2 to 50 times longer than that of non-treated specimens.

Changing Mechanisms of Surface Relief and the Damage Evaluation of Low Cycle Fatigued Austenitic Stainless Steel
Nao Fujimura, Takashi Nakamura, Kosuke Takahashi
MATEC Web of Conferences, 2018年05月25日, EDP Sciences, 英語
2018年05月25日 - 2018年05月25日

高強度鋼の疲労き裂進展特性に及ぼす真空環境の影響―ΔK漸増試験による微小き裂の挙動―
石原 梨沙, メヘンディラッタ パラス, 中村 孝, 藤村 奈央, 髙橋 航圭
M&M材料力学カンファレンス, 2018年, 一般社団法人 日本機械学会, 日本語
2018年 - 2018年, In recent years, it has been revealed that in high strength steel, fracture occurs from non-metallic inclusions inside of the material in the very high cycle region. However, because of the difficulty in directly observing the internal fatigue process, its mechanism is largely unknown. In this study, we try to clarify the internal fatigue process on the basis that the environment around an internal crack is like a vacuum environment. Also, it has been reported that the effect of vacuum environment is more prominent in the initial stages of crack propagation. This suggests that targeting the crack propagation process of small cracks, like that with the same size as a small defect, would shed light on the controlling factors in the internal fatigue process. Thus, we conducted ΔK-increasing tests in air and in vacuum using specimens with a small artificial defect on its surface. As a result, fatigue crack propagation rates in vacuum were lower than that in air. Also, when compared with the results of long cracks, the crack propagation rates in both environments were much higher. However, after eliminating the effect of crack closure for the results of long crack, the crack propagation rates in both environments matched.

高強度鋼の疲労き裂進展特性に及ぼす真空環境の影響-ΔK 漸減試験による長いき裂の挙動-
メヘンディラッタ パラス, 石原 梨沙, 中村 孝, 藤村 奈央, 高橋 航圭
M&M材料力学カンファレンス, 2018年, 一般社団法人 日本機械学会, 日本語
2018年 - 2018年, Sub-surface fractures are known as a characteristic fatigue mode of high strength steel in the very high cycle region. To reveal the mechanism of sub-surface fractures, ΔK-decreasing tests were conducted in high vacuum and air environments based on the idea that sub-surface cracks are exposed to a vacuum-like environment. As a result, fatigue crack growth rates in high vacuum were slower than those in air. In high vacuum, fatigue crack growth still took place at a considerably low rate around 10^-13 m/cycle, and the effective threshold stress intensity factor rage (ΔK_eff) in high vacuum lower to that in air. Unlike in air environment, negligible effects of oxide-induced crack closure in vacuum was considered as the reason for the results. The behavior of fatigue crack growth properties in high vacuum well explained the characteristics of sub-surface crack growths in very high cycle regime.

有限要素解析による樹脂材料の修復特性評価
長谷川 諒, 高橋 航圭, 藤村 奈央, 中村 孝
機械材料・材料加工技術講演会講演論文集, 2018年, 一般社団法人 日本機械学会, 日本語
2018年 - 2018年

両面粘着テープの併用による接着継手の強度向上
菊澤 卓馬, 高橋 航圭, 藤村 奈央, 中村 孝
機械材料・材料加工技術講演会講演論文集, 2018年, 一般社団法人 日本機械学会, 日本語
2018年 - 2018年

Ti-22V-4Alにおける疲労き裂発生過程の観察
鹿島 彰太, 髙梨 圭, 吉中 奎貴, 中村 孝, 藤村 奈央, 髙橋 航圭
M&M材料力学カンファレンス, 2017年, 一般社団法人 日本機械学会, 日本語
2017年 - 2017年, It is generally reported on titanium alloys that crack initiation occurs from a small flat plane called the “facet”. Thus, it is important to investigate facet formation processes in revealing the fatigue characteristics of titanium alloy. In the present work, β type titanium alloy Ti-22V-4Al was investigated in order to elucidate the fatigue crack initiation process. An axial load fatigue test was carried out with an etched specimen in order to examine the positional relationship between the microstructure and crack initiation site (in the grain or at the grain boundary). After the fatigue test, the fracture surface and the specimen surface were observed by using a scanning electron microscope. From the fracture surface observation, four crack propagation traces were observed on the fracture surface. When focusing on the crack initiation site, it was revealed that each crack initiated from a facet. Then, the facet angle was measured as the angle between the loading direction and the normal to the facet plane, which revealed that the shear stress largely contributed to crack initiation. The result of the specimen surface observation demonstrated that crack initiation occurred in β phase without α precipitate rather than at the β grain boundary. Therefore, in this sample material, crack initiated in β phase mainly by the shear stress.

Ti-22V-4Alにおける疲労き裂発生・進展特性
髙梨 圭, 鹿島 彰太, 吉中 奎貴, 中村 孝, 藤村 奈央, 髙橋 航圭
M&M材料力学カンファレンス, 2017年, 一般社団法人 日本機械学会, 日本語
2017年 - 2017年, To investigate the fatigue crack initiation and propagation properties of Ti-22V-4Al, uniaxial fatigue tests and surface observation were carried out. As a result of surface observation, the crack initiation life of each crack was clarified. The cracks initiated at N = 2000 to 8000 cycles. Based on the crack initiation life of each crack, the tendency of crack initiation was investigated using probability paper. As a result, it was shown that the crack initiation life follows the lognormal distribution. Based on the crack propagation observation results, the relationship between the crack growth rate da/dN and the stress intensity factor range ΔK was investigated. As a result, in the small ΔK region, the dispersions of each crack was large. However, with the increase in ΔK, the dispersions became smaller and showed a certain width. Comparing with the same material with different heat treatment samples, da/dN-ΔK relations in large ΔK regions show similar value. So it suggests that crack propagation resistance may not be affected by the precipitation amount of α phase in this material.

AZ31の疲労特性に及ぼすScanning Cyclic Pressの影響
大賀 向陽, 藤村 奈央, 中村 孝, 髙橋 航圭, 和島 達希
M&M材料力学カンファレンス, 2017年, 一般社団法人 日本機械学会, 日本語
2017年 - 2017年, Magnesium alloy is the lightest metal among all practical metals and recognized as a promising material; however, it has a limited use because of the poor fatigue properties. In this study, a new surface modification technique, scanning cyclic press (SCP), was applied to magnesium alloy AZ31 to improve its fatigue properties. SCP scans a metal surface with a vibrating indenter under precise loading control based on a servo testing machine and can apply a variable cyclically compressive load. The surface observation on AZ31 specimens showed an increase in surface roughness of SCP-treated specimens. However, the fatigue life of SCP-treated specimens clearly increased. Microstructure of a cross section of SCP-treated specimen was observed using an optical microscope. A fine mesh-patterned region was formed beneath the surface to a depth of 50 μm. The fracture surface observation showed that the fracture origin of SCP-treated specimens located in subsurface site whereas that of untreated specimens was at the surface of the specimen. The observation also showed a band-like layer just beneath surface in SCP-treated specimen which did not exist in the untreated specimen. The layer corresponded to the mesh-patterned region. The results suggested that SCP changed the surface microstructure of magnesium alloy and suppressed crack initiation from the specimen's surface.

低サイクル疲労を受けたSUS316NGの表面性状変化機構と損傷評価
藤村 奈央, 西塚 祐斗, 中村 孝, 髙橋 航圭
M&M材料力学カンファレンス, 2017年, 一般社団法人 日本機械学会, 日本語
2017年 - 2017年, To quantitatively investigate the cause of the changes in arithmetic mean roughness R_a and arithmetic mean waviness W_a of austenitic stainless steel under low-cycle fatigue loading, precise observation focusing on slip bands and grain deformations was conducted on SUS316NG. During the fatigue tests, the specimen's surface topography was regularly measured using a laser microscope. The surface topographies obtained were analyzed by frequency analysis to separate the surface relief due to persistent slip bands (PSBs) from that due to crystal grain deformation. The height caused by PSBs and that by crystal grain deformation were measured respectively. As a result, the both heights developed with the increase of usage factor (UF). The amount of increase in the heights with respect to UF increased with strain range. The trend of development of both heights was similar with the trend of R_a and W_a. A comparison between R_a and the height caused by PSBs showed that these values strongly correlated with each other. A comparison between W_a and the height caused by crystal grain deformation also showed that these values strongly correlated with each other. Consequently, the surface texture parameters R_a and W_a represent the changes in the heights of surface reliefs due to PSBs and crystal grain deformation.

WAVE PROPAGATION ACROSS THE INTERFACE OF FLUID-STRUCTURE INTERACTION WITH VARIOUS SURFACE CONDITIONS OF SOLID MEDIUM　　　　　　　　　　　　　　　
Tomohisa Kojima, Kazuaki Inaba, Kosuke Takahashi
PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE, 2016, VOL 4, 2017年, 英語
2017年 - 2017年

ポリイミドフィルムにおける膜厚方向破壊靭性の計測と評価
南雲 慶憲, 坂本 悠介, 中村 孝, 藤村 奈央, 髙橋 航圭
M&M材料力学カンファレンス, 2016年, 一般社団法人 日本機械学会, 日本語
2016年 - 2016年, Polyimide (PI) film with a surface small defect subjected to tensile load is fractured by the crack propagation from the defect in the film thickness direction. However, the evaluation method of fracture toughness in this type of fracture hasn’t yet been established. In this paper, SENT tests were carried out using 125 μm-thick PI films with a surface pre-crack having different depths from 10 μm to 60 μm, and fracture processes focusing on crack opening and crack extension were observed with a color 3D laser scanning microscope. Based on the results, fracture toughnesses J_in in the direction of film thickness were calculated by using two different equations for SENT specimen. As a result, J_in values were clarified to have a slight dependency on pre-crack depth. The differences between J_in values calculated by the two equations were considered small, and fracture toughness was in the range from 0.4 to 1 kJ/m².

PS0031-450 水撃波伝播と管壁の連成振動メカニズムの実験的研究　　　　　　　　　　　　　　　
山口 大介, 増子 拓也, 因幡 和晃, 高橋 航圭, 岸本 喜久雄
M&M材料力学カンファレンス, 2015年11月21日, 一般社団法人日本機械学会, 日本語
2015年11月21日 - 2015年11月21日, Water hammer is familiar phenomena in our life while this phenomena causes noises and failures of water plumbing. Previous studies of water hammer revealed that wave speeds were well predicted by a simple theory and pressure surges could be estimated with the speeds by experiments, numerical analysis, and analytic methods. However, the frontal wave shape of water hammer was neglected and its propagation mechanism was not discussed in the simplified theories. This study focus on the frontal mechanism to understand the structure and decrease the damage of the water hammer. In the present study, we visualize the frontal structures in experiments and numerical analysis as well as revealing strain signals of coupled tubes with pressure waves.

OS1519-461 固液連成界面における固体材料の表面状態が波動伝播へ及ぼす影響　　　　　　　　　　　　　　　
小島 朋久, 因幡 和晃, 高橋 航圭, 岸本 喜久雄
M&M材料力学カンファレンス, 2015年11月21日, 一般社団法人日本機械学会, 日本語
2015年11月21日 - 2015年11月21日, Fluid-structure interaction is one of the most important phenomena to be clarified and controlled in many industrial fields. In some problems, interaction mechanism strongly depends on wave propagation across the interface of solid and fluid. Although many studies have been conducted about fluid-structure interaction, the mechanism of wave propagation across to the solid-fluid interface remains unclear. In this study, we investigated the effect of surface conditions such as surface roughness and wettability of solid materials to wave propagation across the interface. The results of the experiments indicated that due to the wettability of the solid surface, the intensity of the cavitation which appeared near the interface was changed and theoretical assumption of the interface continuity may not be valid under some conditions.

OS0414-326 逆解析を利用した気泡崩壊時のマイクロ・スケール衝撃力測定　　　　　　　　　　　　　　　
石井 智弥, 因幡 和晃, 高橋 航圭, 岸本 喜久雄
M&M材料力学カンファレンス, 2015年11月21日, 一般社団法人日本機械学会, 日本語
2015年11月21日 - 2015年11月21日, When cavitation occurs and bubbles collapses in fluid machinery, such as pumps, impact loading due to the bubble collapsing shortens the life time and decreases the performance. Recently, inspection of cavitation-erosion damage inside the pumps has been conducted by direct visual observations after stopping the operation temporarily. In this study, to realize damage monitoring remotely from outside of the machinery, impact load by spark-generated bubble collapse was estimated using inverse analysis. Impact experiments by spark-generated bubbles were conducted with aluminum plate and impact load and point were measured with AE sensors. The effect of impact point in measurement of impact load was confirmed by bubble collapses at different impact points.

OS0511-444 破壊形態を考慮したFe-Al異材接合継手の疲労寿命予測　　　　　　　　　　　　　　　
深澤 大志, 高橋 航圭, 因幡 和晃, 岸本 喜久雄, 橋村 徹
M&M材料力学カンファレンス, 2015年11月21日, 一般社団法人日本機械学会, 日本語
2015年11月21日 - 2015年11月21日, Dissimilar material joint makes a machine light and efficient. Welding is widely used to connect dissimilar materials, but an intermetallic compound produced in the interface and stress specificity at interface end are concerned to decrease the joint strength. It is important to evaluate the strength of welded joint for designing machine and structure. In this study, single lap specimens with welding joint of Fe and Al plates were prepared for a tensile shear test and a fatigue test. Joint strength and interfacial strength were investigated by modifying shape of welding joint. Fracture analysis revealed the interface was brittleness destruction and the joint strength depends on the strength of the starting point of the destruction. Fatigue curve can be classified every destruction form by using the hotspot stress of the starting point of the destruction.

OS13-6 Image Processing Technique of Photoelastic Analysis for Evaluating Stress Transfer at Fiber/Matrix Interface(Interface,OS13 Micro- and meso-mechanics of composites,MICRO AND NANO MECHANICS)　　　　　　　　　　　　　　　
Budiman Bentang Arief, Takahashi Kosuke, Inaba Kazuaki, Kishimoto Kikuo
Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2015年10月04日, 一般社団法人日本機械学会, 英語
2015年10月04日 - 2015年10月04日

S0520302 マグネティックバーチャルチャネルの形成　　　　　　　　　　　　　　　
高橋 龍太朗, 大島 修造, 因幡 和晃, 高橋 航圭
年次大会 : Mechanical Engineering Congress, Japan, 2015年09月13日, 一般社団法人日本機械学会, 日本語
2015年09月13日 - 2015年09月13日, Nonmagnetic fluid can be levitated if a very strong magnetic field is applied by a super-conducting magnet. This study suggests noncontact magnetic virtual channel (MVC) in the casting process of nonconductive materials such as glasses to enable the continuous casting in high quality. In this study, we model the MVC by using a magnetic fluid in a weak magnetic field. A rectangular coil is assumed as a source of the magnetic power. The magnetic field distribution of the rectangular coil was calculated and the distribution of the magnetic force is obtained. To confirm whether a liquid column is stable or not, stability analysis is carried out about a liquid film held by magnetic power. As a result, stability is confirmed and further analysis about the floating position and the cross sectional shape of the floating liquid is done. An experiment to let a nonmagnetic fluid float in magnetic fluid was conducted. Tests were done with distilled water and silicone oil and both liquids can be levitated. Observation suggests that the shape of the floating liquids vary according to the boundary tension. Therefore, this accords with the analysis results qualitatively.

S0520301 容器内二相液体の電磁加振に関する研究　　　　　　　　　　　　　　　
伊藤 怜, 大島 修造, 因幡 和晃, 高橋 航圭
年次大会 : Mechanical Engineering Congress, Japan, 2015年09月13日, 一般社団法人日本機械学会, 日本語
2015年09月13日 - 2015年09月13日, In the field of steelmaking and refining, phosphorus is impurities. The steel is produced by removing reacted with slug to it. Improving the reaction speed of phosphorus contribute significantly to the reduction of steel making process and it can achievement by increase interfacial area between slug and metal. So the purpose of this research is to increase interfacial area efficiently by electromagnetic force (EMF) instead of inert gas. It revealed that it is possible to sloshing of the liquid metal by electromagnetic force in horizontal directions by numerical simulation and increasing the interfacial area during sloshing. Performs approximate analysis by linear theory for horizontal sloshing of the multiliquid-layer and compered with the numerical value. In addition, new vertical sloshing method that is locally applied electric field and magnetic field is devised.

Measurement and visualization of supercrtcal CO2 in dynamic phase transition
Hiroyuki Ushifusa, Kazuaki Inaba, Konosuke Sugasawa, Kosuke Takahashi, Kikuo Kishimoto
EFM14 - EXPERIMENTAL FLUID MECHANICS 2014, 2015年, 英語
2015年 - 2015年

WAVE PROPAGATION ACROSS SOLID-FLUID INTERFACE WITH FLUID-STRUCTURE INTERACTION
Tomohisa Kojima, Kazuaki Inaba, Kosuke Takahashi
PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE - 2015, VOL 5, 2015年, 英語
2015年 - 2015年

動脈瘤を含む脳動脈分岐部まわりの応力の評価　　　　　　　　　　　　　　　
小田 健太郎, 大島 修造, 因幡 和晃, 高橋 航圭
計算力学講演会講演論文集, 2014年11月22日, 一般社団法人日本機械学会, 日本語
2014年11月22日 - 2014年11月22日, Abstract A cerebral aneurysm is a disease in which part of the artery in the brain is enlarged in nodular and causes a subarachnoid hemorrhage when the aneurysm is ruptured. It brings pain to people and death. In this study, in order to compare the stress at the branch in the development process of the aneurysm, numerical simulation was performed using the aneurysm growth model. In the model without aneurysm, large circumferential stress and pressure were acting on the center of the branch. In the aneurysm growth model, the circumferential stress of about 1.5 times of a case without aneurysm was acting upon base of the aneurysm. Therefore we thought the local distention may be involved in the growth and development of cerebral aneurysm. Moreover, it must be necessary to investigate the growth and rupture mechanism of cerebral aneurysm by the simulation using the model of the large aneurysm under the various conditions of the branch vessel diameter ratio and branch angle.

OS1118 毛細管力によるピラーアレイ構造体凝集現象の評価　　　　　　　　　　　　　　　
古田 将一, 高橋 航圭, 因幡 和晃, 岸本 喜久雄
M&M材料力学カンファレンス, 2014年07月19日, 一般社団法人日本機械学会, 日本語
2014年07月19日 - 2014年07月19日, Capillary induced forces are widely observed in fine structures where liquid flows along solid surfaces, such as wet-etching process in micro/nano-pillar fabrication. Undesirable bending or collapse of the structure occurs if they are improperly considered in the structural design. In this study, liquid column formation between aligned polymer plates is observed and the resulting capillary induced force causing the plate deformation is evaluated. The plate dimension is sub-millimeter scale, which is rather large in observation of capillarity, in order to clearly measure deformation process of the aligned plates until their contacts. When the plates are immersed into liquid from the fixed end, gap between plates becomes smaller due to liquid columns formed far from the end. It is found that the deformation of the plates proceeds more unstably as the number of plates increase, but their contact is initiated at the similar plate length into liquid.

OS0304 Fe-Al異材接合継手の強度評価　　　　　　　　　　　　　　　
深澤 大志, 三浦 靖史, 高橋 航圭, 因幡 和晃, 岸本 喜久雄, 橋村 徹
M&M材料力学カンファレンス, 2014年07月19日, 一般社団法人日本機械学会, 日本語
2014年07月19日 - 2014年07月19日, Welding is widely used to connect dissimilar materials, but an intermetallic compound produced in the interface is concerned to decrease the joint strength. It is important to evaluate the strength of welded joint for designing machine and structure. In this study, single lap specimens with welding joint of Fe and Al plates were prepared for a tensile shear test and a fatigue test. Influence of rotation caused by tension and distribution of interfacial strength were investigated by modifying specimen length, number of tabs, and shape of welding joint. It was found that the rotation did not have significant influence on interfacial strength, but fracture behavior varied and indicated uneven strength distribution along interface.

TRANSIENT BEHAVIOR OF WATER HAMMER IN A TWO-PIPE SYSTEM　　　　　　　　　　　　　　　
Kazuaki Inaba, Masaya Kamijukkoku, Kosuke Takahashi, Kikuo Kishimoto
PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE - 2013, VOL 4: FLUID-STRUCTURE INTERACTION, 2014年, 英語
2014年 - 2014年

OS1703 粘着剤のはく離変形挙動の観察によるタック強度評価　　　　　　　　　　　　　　　
山縣 勇一朗, 高橋 航圭, 因幡 和晃, 岸本 喜久雄, 稲男 洋一, 杉崎 俊夫
M&M材料力学カンファレンス, 2013年10月12日, 一般社団法人日本機械学会, 日本語
2013年10月12日 - 2013年10月12日, A tack is important physical property for pressure-sensitive adhesive that shows instantaneous adhesiveness. Recently, thinner adhesive has been developed and often applied in industry while the occurrence and the mechanism of the tack have not been clarified yet. It is known that as adhesive is thinner than 5μm, the tack becomes much weaker. To improve and develop the thin but strong adhesive it is necessary to observe the peeling phenomena of the adhesive. In this study, the aim is to investigate the effect of the adhesive's thickness on peeling behaviors and tack strengths with probe tack tests. We confirmed that as adhesive is thicker, peel force becomes larger but the rate of increase of peel force becomes lower and the amount of adhesive deformation becomes larger. We observed the displacement of fine particles mixed in adhesive. As result, as the particles reaches deeply from the surface of the adhesive to its inside, the displacement of the particles becomes smaller and the movement of the particles isn't seen at 25 μm from the surface.

OS0925 濡れによる液架橋形成が及ぼす平板の変形評価　　　　　　　　　　　　　　　
高橋 航圭, 杉田 精司, 因幡 和晃, 岸本 喜久雄
M&M材料力学カンファレンス, 2013年10月12日, 一般社団法人日本機械学会, 日本語
2013年10月12日 - 2013年10月12日, In a design of fine structures, characteristic phenomena such as surface forces, which are usually negligible in a macroscopic scale, need to be taken into consideration. When a liquid exists between solid surfaces, a liquid column can form in accordance with the balance of their surface energies, called capillarity. In this study, deformation induced by capillarity is quantitatively evaluated. A pair of polymer plates fixed at one end and immersed in liquid, bends because of capillary forces from a liquid column formed between the plates. Although capillary-induced deformation is usually observed at the micro/nano scales, the dimensions of the prepared plate specimens are on the order of millimeters because the larger scale makes observation of the evolving deformation easier. Experimental results indicate that bending proceeds to either contact or collapse the plates if their gap spacing becomes smaller than 2/3 of the initial plate separation, regardless of plate dimensions. This phenomenon is theoretically validated by proposing a dimensionless number, which is derived from a balance of surface energy, potential energy of a liquid, and strain energy of a plate.

OS1005 複合矩形管における水撃波動伝播　　　　　　　　　　　　　　　
武田 健吾, 因幡 和晃, 高橋 航圭, 岸本 喜久雄
M&M材料力学カンファレンス, 2013年10月12日, 一般社団法人日本機械学会, 日本語
2013年10月12日 - 2013年10月12日, Water hammer occurs in a pipe when water flow is suddenly stopped. There are pipes having the square or rectangular cross sectional shape rather than the circular shape: micro channel, gutter, and so on. Moreover, a part of the walls is often composed by different material or different wall thickness. To reveal pressure wave propagation in such a channel, we examined water hammer phenomenon and measured wave speeds in rectangular tubes with different wall materials and thicknesses. We newly proposed theoretical wave speeds based on the classical theory and the junction conditions of two walls: fixed, simply supported, and mixed. We confirmed that theoretical predictions agreed with experimental wave speeds.

補修材料に対する界面強度評価手法の確立　　　　　　　　　　　　　　　
早房敬祐, 中本浩章, 岸本喜久雄, 新井大輔, 因幡和晃, 高橋航圭
日本材料学会学術講演会講演論文集, 2013年
2013年 - 2013年

OS1212 スティックスリップはく離の発生に及ぼす被着体の剛性の影響　　　　　　　　　　　　　　　
熊谷 理, 高橋 航圭, 因幡 和晃, 岸本 喜久雄, 山田 幹典, 谷中 雅顕
M&M材料力学カンファレンス, 2012年09月22日, 一般社団法人日本機械学会, 日本語
2012年09月22日 - 2012年09月22日, The use of thin-film technology has rapidly expanded. Multilayer structures composed of thin film with specific properties are used in many fields, for example liquid crystal displays and solar cells. In a multi-layer structure, the interface between films has the lowest strength, thus the interface strength between film and adhesive is important for designing products and improving interface strength. Peeling test is used widely as a method to measure the interface strength. In that test, stick-slip phenomenon sometimes occurs in particular conditions, and it is difficult to evaluate the interface strength if that happens. Therefore the research about stick-slip behavior in peeling test is important to establish the method measuring the interface strength appropriately. This paper focuses on the relation between adherend stiffness and stick-slip phenomenon, and clarifies the effect of adherend stiffness on stick-slip phenomenon.

OS1208 樹脂系補修材料の剥離強度試験およびその評価方法の検討　　　　　　　　　　　　　　　
中本 浩章, 早房 敬祐, 能見 基彦, 岸本 喜久雄, 因幡 和晃, 高橋 航圭, 新井 大輔
M&M材料力学カンファレンス, 2012年09月22日, 一般社団法人日本機械学会, 日本語
2012年09月22日 - 2012年09月22日, Repair composites has high stiffness and flexible workability. Therefore, they have been used as efficient repair material for surface damages including cracks and erosions. Catalog parameters such as stiffness, water resistance, chemical resistance, and delamination strength. However, catalog delamination strength for lining-application has not been well clarified. In this study, we examined tensile test using particle-reinforced composite material bonded on tensile test pieces. Delamination strength was evaluated by nominal strain and effect of material and surface condition of tensile specimen.

OS0508 表面凹凸化による円管の圧壊特性向上　　　　　　　　　　　　　　　
川北 純, 合田 峻広, 高橋 航圭, 因幡 和晃, 岸本 喜久雄, 橋村 徹
M&M材料力学カンファレンス, 2012年09月22日, 一般社団法人日本機械学会, 日本語
2012年09月22日 - 2012年09月22日, Structural members of automobiles are required to improve collision safety and reduce weight for the purpose of lower fuel consumption. Therefore a thin-walled cylinder which has excellent energy absorption efficiency and lightweight is used for the shock absorber of structural members. This cylinder absorbs impact energy in the continuous plastic buckling distortion caused by axial impact loading. However the load histories of the axial crushing of the cylinder repeat the periodic variation with the local buckling. That is causing the decrease of energy absorption efficiency. For this reason, the design which suppresses variation of load lead to improved energy absorption efficiency. The purpose of this study is to develop members improved the stability of load. We examined the optimal cross-sectional shape of the cylinder to reduce the load variation with FEM analysis.

OS0113 ピラーアレイの変形に及ぼす液体架橋による表面張力の影響　　　　　　　　　　　　　　　
杉田 精司, 高橋 航圭, 因幡 和晃, 岸本 喜久雄
M&M材料力学カンファレンス, 2012年09月22日, 一般社団法人日本機械学会, 日本語
2012年09月22日 - 2012年09月22日, Structural interaction between solids and liquids are seen in various industrial fields, such as MEMS fabrication. A droplet between solid surfaces forms a liquid bridge, which provides a resistive or a desorption force due to surface tension. These forces can be ignored in large scale structures, but they show significant influence in micro scale. Since the deformation caused by liquid bridge has not been sufficiently studied, it is necessary to quantitatively evaluate these forces. In this study, two pillars that were aligned in parallel were prepared and the deformation caused by a liquid bridge was observed with different types of liquid. It is confirmed that the spacing between two pillars were getting closer and eventually attached with each other when silicone oil was used as liquid. But water did not cause any change in two pillars. The evaluation of the pillar deformation was conducted using a cantilever model, considering Laplace pressure and surface tension as drive forces. As a result, it was found that Laplace pressure has more significant influence than surface tension.

109 樹脂系補修材料に対する界面強度評価手法の検討(薄膜・界面強度,破壊の発生・進展とその解析・評価・計測,オーガナイスドセッション7)
早房 敬祐, 中本 浩章, 岸本 喜久雄, 新井 大輔, 因幡 和晃, 高橋 航圭
学術講演会講演論文集, 2012年, 日本材料学会, 日本語
2012年 - 2012年

PS06 抵抗温度特性利用の電気抵抗変化法によるCFRPの統計的損傷診断(ポスターセッション)　　　　　　　　　　　　　　　
鈴木 良郎, 轟 章, 高橋 航圭, 水谷 義弘, 松崎 亮介
M&M材料力学カンファレンス, 2009年07月24日, 一般社団法人日本機械学会, 日本語
2009年07月24日 - 2009年07月24日, The present study employs the delamination detection in CFRP laminates using electrical resistance changes. Although the method detects the delamination without expensive sensors, the electrical resistance changes only due to electrode's damage make a wrong diagnosis. A delamination detection using statistical analysis of temperature characteristic of resistance changes is developed. CFRP laminates are heated up by applying electric currents through the electrodes mounted on the surface of the structure. When the delamination occurs, the electrical resistance change due to elevated temperature becomes different from that of the other intact parts. A statistical analysis method detects the change. The electrical resistance changes due to electrode's damage don't affect the temperature characteristic of resistance. The present study employs the new method for the delamination detection of cross-plied CFRP beams. In this study, the method is applied for quasi-isotropic CFRP plates. The detection limit of the method is investigated, and the effect of electrode's damage on the diagnosis is discussed.

P006 電気抵抗変化の温度依存性を利用したCFRPの統計的損傷検知(フェロー賞表彰対象ポスターセッション)　　　　　　　　　　　　　　　
高橋 航圭, 轟 章, 島村 佳伸, 岩崎 篤, 松崎 亮介
M&M材料力学カンファレンス, 2007年10月24日, 一般社団法人日本機械学会, 日本語
2007年10月24日 - 2007年10月24日, The damage detection system of CFRP structures by making use of electrical resistance changes due to elevated temperature is performed. CFRP is heated up by applying electric currents through the electrodes mounted on the surface of the structure. When the delamination occurs, the electrical resistance change due to elevated temperature becomes different from that of the other intact parts. In this study, therefore, the electrical resistance changes are measured at the multiple segments on a CFRP beam simultaneously, and the damage is detected from the change of relative relationship between the measurements. A set of electrical resistance changes is related with each other by means of a response surface, which changes when delamination cracks occur. The similarity of the response surfaces is evaluated by F statistics. These damage detection systems are applied to detect a delamination in cross-plied CFRP beam and the delamination is successfully identified.

Statistical damage detection of laminated CFRP beam using electrical resistance change method　　　　　　　　　　　　　　　
Kosuke Takahashi, Akira Todoroki, Yoshinobu Shimamura, Atsushi Iwasaki
PROGRESSES IN FRACTURE AND STRENGTH OF MATERIALS AND STRUCTURES, 1-4, 2007年, 英語
2007年 - 2007年

510 CFRP構造の損傷検知への電気抵抗変化を用いた統計的診断手法の適用(OS8:接合・複合材料の強度と力学(2),学術講演)
轟 章, 高橋 航圭, 岩崎 篤
埼玉ブロック大会(講演会)講演論文集, 2005年, 日本機械学会関東支部, 日本語
2005年 - 2005年

高分子材料工学特論　　　　　　　　　　　　　　　
北海道大学
2021年04月 - 現在

計算工学A　　　　　　　　　　　　　　　
北海道大学
2019年10月 - 現在

材料強度学　　　　　　　　　　　　　　　
北海道大学
2016年04月 - 現在

Strength and Fracture of Materials　　　　　　　　　　　　　　　
Hokkaido University
2016年04月 - 2021年03月

計算固体力学特論　　　　　　　　　　　　　　　
北海道大学
2017年04月 - 2020年03月

材料力学I　　　　　　　　　　　　　　　
北海道大学
2017年04月 - 2020年03月

材料力学概論　　　　　　　　　　　　　　　
東京工業大学

エポキシ樹脂のミクロゲル構造に起因する接着界面の初期き裂発生機構解明
科学研究費助成事業
2024年04月01日 - 2028年03月31日
高橋 航圭
日本学術振興会, 基盤研究(B), 北海道大学, 24K00752

実験と数値解析の融合による粘着・剥離現象の多階層動力学に関する研究
科学研究費助成事業
2024年04月01日 - 2027年03月31日
山口 哲生, 齊藤 尚平, 高橋 航圭
日本学術振興会, 基盤研究(B), 東京大学, 24K00595

CFRPの疲労劣化の機構解明と余寿命推定法の確立
戦略的な研究開発の推進 未来社会創造事業 探索加速型
2022年 - 2026年
荒井 政大
CFRPは、飛行機や自動車等において大幅な軽量化が期待でき、その結果として全世界の二酸化炭素排出量を有効に低減できる材料として期待されている。機体の使用寿命を延ばすことでさらなるCO2排出量の低減を実現するためには、これらの機器の長期使用における損傷評価と余寿命の評価が極めて重要である。本研究ではこれらのCFRPに生じる損傷の発生と進展のメカニズムを詳細に解明し、損傷と破壊のモデルを構築する。さらにはCFRPの疲労劣化診断技術を確立し、疲労・破壊の評価モデルと組み合わせることで、高精度な余寿命評価を実現する。疲労・破壊モデルとエントロピー・電子スピン・熱伝導率等の物性評価手法を有効に組み合わせることで、CFRPの損傷進展とその余寿命を適切に評価し、最終的に機器の使用総寿命を2倍に伸ばすことが可能なモノづくりを提案する。
科学技術振興機構, 名古屋大学

粘着界面のはく離メカニズムに基づくはく離強度評価指標の確立
科学研究費助成事業 基盤研究(C)
2021年04月 - 2024年03月
高橋 航圭
本研究では，力と変形量の関係に基づく材料力学的な観点から，粘着テープの粘着界面におけるはく離メカニズムを明らかにし，それに基づく汎用的かつ簡便なはく離強度評価指標の確立を目的とする．はく離力が，粘着剤層と被着体の間の界面力，粘着剤層の伸縮，テープ基材の曲げ変形に起因する点に着目し，はく離力におけるこれらの寄与を個別に評価する独自手法に取り組む．
これまでに，粘着剤層で消費されたはく離エネルギーと粘着剤層のひずみ速度に着目して実験を行った．テープ材料・テープ厚さ・はく離速度・はく離角度を変えたピール試験とプローブタック試験を行い，両者の関係を調べた．結果，ピール試験，プローブタック試験ともに定常的な界面はく離を示し、ひずみ速度が0.01から100 1/sの広い範囲で，それぞれから得たはく離エネルギーとひずみ速度の関係は同等となり，両対数軸上における直線関係を見出すことができた．
この直線関係は，既往の研究成果から粘弾性のべき乗則に基づく結果であることを確認し，はく離過程における粘着剤層の伸縮過程と関連付けることができた．また，粘着剤層が薄い場合には，はく離界面でキャビティが生じやすく，これによってはく離に要する外部仕事が小さくなることも明らかとなった．今後は，はく離過程におけるキャビティの発生有無をはく離領域における粘着剤層内の応力分布と関連付け，破壊力学的な観点から粘着界面のはく離現象にアプローチする．
日本学術振興会, 基盤研究(C), 北海道大学, 21K03765

ナノ界面の疲労損傷検出と抑制による複合材料の超長寿命化技術
戦略的創造研究推進事業 個人型研究(さきがけ)
2020年11月 - 2024年03月
科学技術振興機構, 北海道大学, 研究代表者

微細多孔薄膜粘着シートの併用による接着性能強化技術の開発
研究成果最適展開支援プログラム(A-STEP) トライアウト
2020年11月 - 2022年03月
科学技術振興機構, 北海道大学, 研究代表者

固体表面へのぬれ性に着目した粘着界面におけるはく離進展クライテリアの確立
科学研究費助成事業 若手研究
2018年04月01日 - 2020年03月31日
高橋 航圭
今年度は、粘着剤のはく離試験の高精度化に向けて、試験機の整備に注力した。まず、はく離角度可変のピール試験機を導入し、高倍率マイクロスコープと併用することで、粘着剤のはく離力と変形の同時測定ができるようになった。さらに、万能試験機を応用してプローブタック試験を行うため、粘着テープの冶具と支持台、ならびに円柱と球状のプローブを作成した。これら試験機の性能を確認するため、試料として同種のモノマーを異なる重合度で合成したゴム系の粘着剤を用意し、厚さ25um、50umのPET基材に塗工して試験を行った。同種のモノマーであることから被着材へのぬれ性は同等で、異なる重合度によって変形抵抗の違いを狙ったサンプルである。
ピール試験の結果、厚さ50umのPET基材の場合には、重合度の違いに関わらずはく離荷重は同程度であった。厚さが25umのPET基材の場合、どちらの粘着剤もはく離荷重は増加したが、重合度の小さい粘着剤の方が大きなはく離荷重を示した。PET基材が薄くなることで、はく離時の粘着剤のひずみ速度が大きくなるため、重合度の低下に伴う粘性効果の増大によりはく離荷重が大きくなったと考えられる。プローブタック試験は、測定精度向上のために検討を続けている段階であるが、マイクロスコープの観察結果からはく離過程におけるキャビティの生成に違いを確認することができている。
また、はく離シミュレーションによる妥当性の検証に向け、ピール試験の有限要素モデルを作成し、粘着剤の粘弾性を考慮したはく離解析が行えるようになった。
日本学術振興会, 若手研究, 北海道大学, 18K13652

表面エネルギーを考慮した微小構造体の力学理論の構築と形態制御への応用
科学研究費助成事業 若手研究(B)
2015年04月01日 - 2018年03月31日
高橋 航圭
本研究では，固体表面のぬれ性に着目し，液面に浮かべたフィルムの中央部を引き上げることで円筒状の立体構造を形成する方法を提案した．様々な寸法のプラスチックフィルム，ゴムシートで実験を行った結果，適切な寸法を選択することで，円筒状構造が形成可能であることを示した．また，液体とフィルムの物性値，寸法を用いて，形成される円筒状構造の解析解ならびに形成に必要なフィルム厚さの条件を導出することができた．さらに，グラフェンシートからも円筒状構造が形成可能なことを，シミュレーションにより示した．
日本学術振興会, 若手研究(B), 北海道大学, 15K17934

Evaluation of tack strength by criterion of cavity generation　　　　　　　　　　　　　　　
研究者海外派遣援助
2016年09月 - 2016年09月
公益財団法人村田学術振興財団, 北海道大学, 研究代表者

動的荷重下における繊維強化複合材料の繊維/樹脂界面特性評価に関する研究　　　　　　　　　　　　　　　
第56回工学研究助成
2013年04月 - 2015年03月
高橋 航圭
みずほ学術振興財団, 研究代表者, 競争的資金

損傷検知・修復機能を有する複合材料構造物の開発　　　　　　　　　　　　　　　
二国間交流事業（韓国との共同研究）
2012年07月 - 2014年06月
高橋 航圭
日本学術振興会, 研究代表者, 競争的資金

液体のぬれが及ぼす構造体変形現象のマクロスケール観察による定式化と無次元数を用いたマイクロ・ナノデバイスへの適用性に関する研究　　　　　　　　　　　　　　　
第29回（2013年度）マツダ研究助成
2013年04月 - 2014年03月
高橋 航圭
公益財団法人マツダ財団, 研究代表者, 競争的資金

電気抵抗変化法を用いたCFRPの統計的損傷検知
科学研究費助成事業 特別研究員奨励費
2008年 - 2008年
高橋 航圭
日本学術振興会, 特別研究員奨励費, 東京工業大学, 08J07083

骨材抽出装置及び骨材抽出方法　　　　　　　　　　　　　　　
特許権, 長尾 莉希, 佐藤 亘, 高橋 航圭, 清水建設株式会社, 国立大学法人北海道大学
特願2023-74294, 2023年04月28日
特開2024-158776, 2024年11月08日

Method of designing composite material, method of evaluating composite material, and composite material　　　　　　　　　　　　　　　
特許権, Sota KAMO, Kiyoka TAKAGI, Tooru SHITANI, Toshio Abe, Sae OBATA, Kosuke Takahashi
特願16 / 059,207, 2018年08月09日
特許US 11,292,576 B2, 2022年04月05日

複合材の設計方法、複合材の評価方法及び複合材　　　　　　　　　　　　　　　
特許権, 加茂宗太, 高木清嘉, 志谷徹, 阿部俊夫, 小畠彩英, 高橋航圭
特願P2017-157393, 2017年08月17日
特許P6980454
2021年12月15日

2013年04月 - 現在
船井情報科学振興財団 奨学事業選考委員
海外大学への留学を目指す積極的で意欲ある優秀な学生に授業料、生活費などの奨学金を支給することにより、若者の留学意欲を高め、広い視野をもった人材の育成に貢献する活動です。