"published_papers" "Title(English)","Title(Japanese)","Author(s)(English)","Author(s)(Japanese)","Journal name(English)","Journal name(Japanese)","Volume","Number","First page","Last page","Date of publication","Peer reviewed/Not peer reviewed","Invited/Not invited","Publishing type","Language","ISSN","DOI","URL","Description(English)","Description(Japanese)" "Effect of stress ratio on the fatigue fracture mechanism of adhesive single-lap joints: in case of GF/PP plates and an acrylic-based structural adhesive","Effect of stress ratio on the fatigue fracture mechanism of adhesive single-lap joints: in case of GF/PP plates and an acrylic-based structural adhesive","Hiroyuki Oguma, Kimiyoshi Naito","Hiroyuki Oguma, Kimiyoshi Naito","Procedia Structural Integrity","Procedia Structural Integrity","","","224","230","2019","TRUE","","international_conference_proceedings","eng","","10.1016/j.prostr.2019.12.024","","Applications of bonding technology have been expanded for lightweight structures and multi-material designs; however, the strength estimation and design method for bonded structures have not been fully established. New design concepts and standards related to strength and reliability are required from industries. In this work, fatigue tests under different stress ratio conditions and fracture surface observations were carried out to investigate the influence of the stress ratio on the fracture mechanism of adhesively bonded structures. Tested material was a glass-fiber-reinforced polypropylene composite plate, and adhesive was an acrylic-based structural adhesive. With single-lap joint specimens, fatigue tests were conducted using uniaxial electro-hydraulic fatigue testing system; frequency was f = 10 Hz, and stress ratios were R = −1, −0.5, 0.1, 0.5, 0.7, and 0.9. The effects of mean load were observed under higher stress ratio conditions, and fatigue strength at 107 (10 million) cycles dramatically deceased when the stress ratio was larger than 0.5. Fracture surface observations revealed correlation between the fatigue properties and fracture mechanism.","" "Effects of mean stress on fatigue properties of carbon/glass fiber hybrid rod","炭素繊維/ガラス繊維ハイブリッド線材の疲労強度特性に及ぼす平均応力の影響","小熊 博幸, 内藤 公喜","小熊 博幸, 内藤 公喜","第42回複合材料シンポジウム前刷り集(Web)","第42回複合材料シンポジウム前刷り集(Web)","","","99999-1","99999-2","2017-09-01","TRUE","","international_conference_proceedings","jpn","","","","","土木ならびに建築分野での利用を想定して開発が進められている炭素繊維/ガラス繊維ハイブリッド線材を対象として,種々の応力比のもとで疲労試験を実施した.そして,平均応力が線材の疲労特性に与える影響について検討した." "Mechanical Properties of Novel Carbon/Glass Hybrid Thermoplastic Composite Rods","Mechanical Properties of Novel Carbon/Glass Hybrid Thermoplastic Composite Rods","NAITO, Kimiyoshi, OGUMA, Hiroyuki, KiyoshiUSAWA","NAITO, Kimiyoshi, OGUMA, Hiroyuki, KiyoshiUSAWA","JISSE15-proceedings-WEB","JISSE15-proceedings-WEB","","","1","6","2017-11-01","TRUE","","international_conference_proceedings","eng","","","","A new thermoplastic epoxy resin has been recently developed by Nagase ChemteX Corporation. Additionally, novel carbon/glass hybrid thermoplastic composite rods called “CABKOMA” have been developed by Komatsu Seiren Co., Ltd. The hybrid rods are a core-in-sheath type and consist of a bundle (or bundles) of carbon fiber surrounded by an outer braided bundle glass fiber in which a new thermoplastic epoxy resin is evenly impregnated as the matrix. The new thermoplastic epoxy resin remains thermoplastic even after curing. In the present work, fundamental research on novel carbon/glass hybrid thermoplastic composite rods was carried out. The morphology of the hybrid rods was observed. Static and fatigue mechanical properties were also investigated.","" "Effect of temperature on interfacial shear properties of carbon/glass hybrid composite rods","炭素繊維/ガラス繊維ハイブリッド複合材料ロッドの界面せん断特性に及ぼす試験温度の影響","内藤 公喜, 田中 義久, 小熊 博幸","内藤 公喜, 田中 義久, 小熊 博幸","第42回複合材料シンポジウム前刷り集(WEB)","第42回複合材料シンポジウム前刷り集(WEB)","","","1","2","2017-09-01","TRUE","","international_conference_proceedings","jpn","","","","","炭素繊維/ガラス繊維ハイブリッド樹脂複合材料ロッドの荷重負荷時には、ガラス繊維部から界面を通して負荷が炭素繊維部に伝達される。本研究では炭素繊維部/ガラス繊維部の界面のせん断特性に及ぼす試験温度の影響について調べた。" "EXPERIMENTAL INVESTIGATION ON THE FORMATION MACHANISM OF DISTINCTIVE FRACTURE SURFACE IN SUB-SURFACE FRACTURE","EXPERIMENTAL INVESTIGATION ON THE FORMATION MACHANISM OF DISTINCTIVE FRACTURE SURFACE IN SUB-SURFACE FRACTURE","OGUMA, Hiroyuki","OGUMA, Hiroyuki","Proceedings of 14th International Conference on Fracture (ICF14)","Proceedings of 14th International Conference on Fracture (ICF14)","","","9999-1","9999-2","2017-03-01","TRUE","","international_conference_proceedings","eng","","",""," Mechanism in the sub-surface fracture of titanium alloy in the very high cycle fatigue has been experimentally investigated. Test pieces with smooth and rounded surfaces were repeatedly contacted in vacuum environment. As a result, fine surface asperities were observed on the contact surfaces which was quite similar to that observed in the sub-surface fractures. Microstructure refinements and metallic adhesion under compression loadings in vacuum-like environment are key phenomena for the formation of the granular region in the sub-surface fracture.","" "DATA ACQUISITION FOR VERY HIGH CYCLE FATIGUE OF NON-FERROUS METALLIC MATERIALS BASED ON THE COLLABORATIVE RESEARCH IN JSMS - 3rd Report: Effect of loading type and test frequency on VHCF properties of beta Ti22V4Al alloy","DATA ACQUISITION FOR VERY HIGH CYCLE FATIGUE OF NON-FERROUS METALLIC MATERIALS BASED ON THE COLLABORATIVE RESEARCH IN JSMS - 3rd Report: Effect of loading type and test frequency on VHCF properties of beta Ti22V4Al alloy","OGUMA, Hiroyuki, Takashi NAKAMURA, Akira UENO, Takashi MATSUMURA, Kiyotaka MASAKI, Hiroyuki AKEBONO, Yoshihiko UEMATSU, Noriyasu OGUMA, Toshifumi KAKIUCHI, Yoshinobu SHIMAMURA, Yuki NAKAMURA","OGUMA, Hiroyuki, Takashi NAKAMURA, Akira UENO, Takashi MATSUMURA, Kiyotaka MASAKI, Hiroyuki AKEBONO, Yoshihiko UEMATSU, Noriyasu OGUMA, Toshifumi KAKIUCHI, Yoshinobu SHIMAMURA, Yuki NAKAMURA","VHCF7 Seventh International Conference on Very High Cycle Fatigue","VHCF7 Seventh International Conference on Very High Cycle Fatigue","","","205","210","2017-07-01","TRUE","","international_conference_proceedings","eng","","","","Very high cycle fatigue (VHCF) in high strength materials becomes recognized as one of the major issues for long-term reliability in mechanical engineering. The VHCF is characterized by failures in lower stress levels than common fatigue strength determined by surface fractures, and in that region, the failures occur from sub-surface of materials. There are many studies on VHCF, however, ferrous metals have mainly been investigated. Fatigue test data of non-ferrous metals in very high cycle regime are still limited. Previously, mechanisms of sub-surface crack initiation and growth have been proposed, however, a unified theory of sub-surface fracture in high strength materials remains to be developed. Therefore, theoretical method of evaluation for strength and fatigue life in very high cyc","" "Flexural Properties of Novel Carbon/Glass Hybrid Composite Rods","Flexural Properties of Novel Carbon/Glass Hybrid Composite Rods","NAITO, Kimiyoshi, TANAKA, Yoshihisa, OGUMA, Hiroyuki","NAITO, Kimiyoshi, TANAKA, Yoshihisa, OGUMA, Hiroyuki","","","","","","","2017-09-04","TRUE","","international_conference_proceedings","eng","","","","In the present work, fundamental research on novel carbon/glass hybrid thermoplastic composite rods was carried out. The morphology and flexural properties of the novel carbon/glass hybrid thermoplastic composite rods were evaluated. The longitudinal and cross-sectional morphology of the hybrid rods were observed using a digital microscope. Static and fatigue flexural properties were also investigated.","" "TENSILE PROPERTIES OF NOVEL CARBON/GLASS HYBRID THERMOPLASTIC COMPOSITE RODS UNDER STATIC AND FATIGUE LOADING","TENSILE PROPERTIES OF NOVEL CARBON/GLASS HYBRID THERMOPLASTIC COMPOSITE RODS UNDER STATIC AND FATIGUE LOADING","NAITO, Kimiyoshi, OGUMA, Hiroyuki","NAITO, Kimiyoshi, OGUMA, Hiroyuki","Proceedings of BCCM-3 (USB)","Proceedings of BCCM-3 (USB)","","","1","7","2016-08-01","TRUE","","international_conference_proceedings","eng","","","","Novel carbon/glass hybrid thermoplastic composite rods have been developed, and they consist of PAN-based carbon fiber, E-class glass fiber, and thermoplastic resin. Three types of hybrid rod with different carbon/glass ratios were fabricated. Surface and cross-sectional morphologies of the hybrid rods were observed using a digital microscope, and volume fractions of carbon/glass fibers, matrix, and void were determined by the specific gravity measurement and the thermogravimetric analysis.","" "Lap shear strength of similar GF/PP adherends boned with two-part acrylic-based adhesive","Lap shear strength of similar GF/PP adherends boned with two-part acrylic-based adhesive","NAITO, Kimiyoshi, OGUMA, Hiroyuki","NAITO, Kimiyoshi, OGUMA, Hiroyuki","ECCM17 - 17th European Conference on Composite Materials Proceeding WEB","ECCM17 - 17th European Conference on Composite Materials Proceeding WEB","","","1","4","2016-06-01","TRUE","","international_conference_proceedings","eng","","","","In the present work, the lap shear strength and fracture behavior of two-part acrylic-based adhesive was investigated. Shear tests were carried out using single lap joints. Commercially available acrylic adhesive (DP-8005) was used as adhesive. Glass fabric reinforced polypropylene matrix composite (GF/PP: TEPEX dynalite 104-RG600(x)/47%) was used as adherends. Aluminum alloy (5052-H34: surface was sandblasted with acetone cleaning) was also used as adherends for comparison purpose. Three types of surface treatment were prepared: as-received with ethanol cleaning, as-received with acetone cleaning, sandblasted with acetone cleaning.","" "MECHANICAL PROPERTIES OF NOVEL CARBON/GLASS FIBER HYBRID ROD FOR TENDONS","テンドン用炭素繊維/ガラス繊維複合材料の機械的性質","OGUMA, Hiroyuki, NAITO, Kimiyoshi","OGUMA, Hiroyuki, NAITO, Kimiyoshi","Proceedings of ECCM17 - 17th European Conference on Composite Materials","Proceedings of ECCM17 - 17th European Conference on Composite Materials","","","1","7","2016-05-01","TRUE","","international_conference_proceedings","eng","","","","In the present work, novel carbon/glass hybrid thermoplastic composite rods have been developed, which consist of PAN-based carbon fiber, E-class glass fiber, and thermoplastic. Three types of the hybrid rod with different carbon/glass ratios were fabricated. To investigate mechanical properties of the hybrid rods, tensile tests, fatigue tests and observations were conducted.","" "TENSILE PROPERTIES OF CARBON NANOTUBES-SHEETS/CARBON FIBERS/EPOXY AND CARBON NANOTUBES-GRAFTED CARBON FIBERS/EPOXY HYBRID COMPOS","TENSILE PROPERTIES OF CARBON NANOTUBES-SHEETS/CARBON FIBERS/EPOXY AND CARBON NANOTUBES-GRAFTED CARBON FIBERS/EPOXY HYBRID COMPOS","NAITO, Kimiyoshi, VikumPremalal, OGUMA, Hiroyuki, YoshinobuShimamura, YokuInoue","NAITO, Kimiyoshi, VikumPremalal, OGUMA, Hiroyuki, YoshinobuShimamura, YokuInoue","ICCM20 FINAL PROGRAM including Full papers (WEB Download)","ICCM20 FINAL PROGRAM including Full papers (WEB Download)","","","9999-1","9999-8","2015-07-01","TRUE","","international_conference_proceedings","eng","","","","In this study, the tensile properties of carbon fiber reinforced polymer matrix composites incorporating CNTsheets (CNT-sheets/carbon fibers/epoxy hybrid composites) and CNT-grafted carbon fibers (CNT-grafted carbon fibers/epoxy hybrid composites) were investigated. For the CNT-sheets/carbon fibers/epoxy hybrid composites, the tensile modulus of hybrid composites was higher than that in the as-received state. The tensile strength of CNTsheets/polyacrylonitrile (PAN)-based carbon fibers/epoxy hybrid composite was lower than that in the as-received state and the tensile strength of CNT-sheets/pitch-based carbon fibers/epoxy hybrid composite was higher than that in the as-received state.","" "Tensile properties of novel carbon/glass hybrid thermoplastic composite rods for tendon","Tensile properties of novel carbon/glass hybrid thermoplastic composite rods for tendon","OGUMA, Hiroyuki, NAITO, Kimiyoshi","OGUMA, Hiroyuki, NAITO, Kimiyoshi","LIMAS2015 Official Conference Proceedings","LIMAS2015 Official Conference Proceedings","","","21","26","2015-11-01","TRUE","","international_conference_proceedings","eng","","","","The tensile properties of novel carbon/glass hybrid thermoplastic composite rods were investigated. The tensile strengths of the hybrid rods have more than 1 GPa. The Weibull statistical distributions of tensile strength for the hybrid rods were also examined.","" "Interfacial shear properties of carbon nanotubes grafted carbon fiber polyimide composites","Interfacial shear properties of carbon nanotubes grafted carbon fiber polyimide composites","NAITO, Kimiyoshi, OGUMA, Hiroyuki","NAITO, Kimiyoshi, OGUMA, Hiroyuki"," Proceedings of ICCST/10 (WEB)"," Proceedings of ICCST/10 (WEB)","","","1","6","2015-09-01","TRUE","","international_conference_proceedings","eng","","","","In the present work, the interfacial shear strength and fracture behavior of CNT-grafted high tensile strength polyacrylonitrile (PAN) -based and high modulus pitch-based carbon fiber polyimide composites were investigated. Interfacial shear tests of CNT-grafted and as-received PAN- and pitch-based carbon fiber polyimide composites were performed using an interfacial micro-bond (microdroplet) evaluation instrument. The results clearly demonstrated that the grafting of CNT are effective in improving the interfacial shear strength of PAN- and pitch-based carbon fiber polyimide composites.","" "Quantitative Evaluation of Surface Relief Low Cycle Fatigued Austenitic Stainless Steel","低サイクル疲労損傷を受けたオーステナト系ンレ鋼におる表面性状の定量的評価","信耕友樹, 藤村奈央, 中田康敬, 小熊 博幸, 中村 孝","信耕友樹, 藤村奈央, 中田康敬, 小熊 博幸, 中村 孝","M&M2014材料力学カンファレンス論文集","M&M2014材料力学カンファレンス論文集","","","9999","9999","2014-07-01","FALSE","","international_conference_proceedings","jpn","","","",""," SUS316NGを対象として低サイクル疲労試験を行い,試験中に変化する表面凹凸を測定した.得られた表面凹凸において,すべり帯による凹凸および結晶粒の変形・回転による凹凸の発達度合いをそれぞれ算術平均粗さRaおよび算術平均うねりWaとして定量的に評価した.その結果,疲労累積係数UFの増加に伴って,RaおよびWaは増加した.また,繰返し負荷の大きさによってRaおよびWaの変化傾向に違いが見られた.この変化傾向の違いを利用することで,損傷を受けた機器のRaおよびWaを測定し,UFおよび繰返し負荷の大きさを推定できる可能性がある." "An Attempt to Accumulate Very High Cycle Fatigue Data of Non-Ferrous Metal Materials","非鉄金属材料における超高サイクル疲労データ蓄積の試み","曙 紘之, 上野 明, 小川武史, 小熊規泰, 小熊 博幸, 柿内利文, 菊池将一, 塩澤和章, 島村佳伸, 中島正貴, 中村裕紀, 西田友久, 政木清孝, 松村 隆, 中村 孝","曙 紘之, 上野 明, 小川武史, 小熊規泰, 小熊 博幸, 柿内利文, 菊池将一, 塩澤和章, 島村佳伸, 中島正貴, 中村裕紀, 西田友久, 政木清孝, 松村 隆, 中村 孝","第32 回疲労シンポジウム","第32 回疲労シンポジウム","","","9999","9999","2014-11-01","TRUE","","international_conference_proceedings","jpn","","","","","非鉄金属材料の超高サイクル疲労データを系統的に取得し,それらに及ぼす影響因子を明らかにすることを目的として,日本材料学会疲労部門委員会に超高サイクル疲労研究分科会が設立された.本研究会ではMg合金,鋳造アルミ合金,βチタン合金を対象として107以上の領域を含む基礎S-N線図を取得し,これらに及ぼす負荷形式の影響や破面との相関を明らかにし,超高サイクル疲労強度評価法の構築を目指す.本報告では現状までに得られたデータに基づき,本分科会の研究概要を報告する." "Effects of Vacuum Environment on Small Fatigue Crack Propagation of Ti-6Al-4V Alloy","Ti-6Al-4V合金における微小疲労亀裂進展に及ぼす真空環境の影響","髙久和明, 中村 孝, 小熊 博幸","髙久和明, 中村 孝, 小熊 博幸","M&M2014 カンファレンス","M&M2014 カンファレンス","","","OS2105-1","OS2105-3","2014-07-01","FALSE","","international_conference_proceedings","jpn","","","","","チタン合金は超高サイクル域で内部起点型疲労破壊を生じる.一方,内部亀裂周囲環境は真空環境に近いと考えられる.そこで,微小亀裂進展に及ぼす真空環境の影響を明らかにするため,表面に微小円孔を加工した試験片を用い,真空環境および大気環境の下で軸荷重疲労試験を実施した.並行して亀裂進展挙動の観察を行い,亀裂進展速度を測定した.その結果,真空環境では大気環境と比べ亀裂進展速度が著しく低下した.また,大亀裂とは異なる微小亀裂特有のふるまいが,大気環境に比べて真空環境においてより顕著に表れることが示された." "Changes in Surface Roughness of Low Cycle Fatigued SUS316NG under Two-step Variable Strain Ranges","SUS316NGの二段二重低サイクル疲労における表面粗さの変化","FUJIMURA Nao, NAKAMURA Takashi, OGUMA, Hiroyuki, NIINUMA Tadaki","FUJIMURA Nao, NAKAMURA Takashi, OGUMA, Hiroyuki, NIINUMA Tadaki","M&M2014 カンファレンス講演論文集","M&M2014 カンファレンス講演論文集","","","9999","9999","2014-07-01","TRUE","","international_conference_proceedings","eng","","","","SUS316NGを用いて,大きさの異なる2種類のひずみ範囲の下でこれらの付与履歴を変えた二段二重疲労試験を行い,表面粗さの変化を調べた.また,表面観察を行い,ひずみ履歴が表面粗さの変化に及ぼす影響を検討した.その結果,負荷ひずみの大きさによって表面凹凸の変化量が異なるため,各段での表面粗さの増加率が変化した.各段での粗さの増加率は,各ひずみ範囲一定の下で得られる増加率とほぼ一致したことから,ひずみ履歴が変化する場合の表面粗さの変化傾向は,ひずみ範囲一定条件での傾向を付与履歴順に重ね合わせることで記述できる.",""