PUBLICATIONS

2019

• Hiroyuki Hirakata, Kenta Konishi, Toshiyuki Kondo and Kohji Minoshima, "Electron-beam enhanced creep deformation of amorphous silicon nano-cantilever", Journal of Applied Physics, Vol. 126 (2019), 105102. [Link]
• Toshiyuki Kondo, Daiki Miki, Hiroyuki Hirakata and Kohji Minoshima, "Effects of surface oxide layer on fracture toughness of submicrometer-thick freestanding copper films", Engineering Fracture Mechanics, Vol. 220 (2019), 106652. [Link]
• Toshiyuki Kondo, Akihiro Shin, Masaya Akasaka, Hiroyuki Hirakata and Kohji Minoshima, "Vacuum effects on fatigue crack growth in submicrometre-thick freestanding copper films", Fatigue & Fracture of Engineering Materials & Structures, Vol. 42 (2019), pp. 1118-1129. [Link]

2018

• Hiroyuki Hirakata, Takashi Kawai, Toshiyuki Kondo and Kohji Minoshima, "Plastic deformation dominates chemical reactions in Ti/Si multilayered nanofilms", Materials Science and Engineering: A, Vol. 737 (2018), pp. 105-114. [Link]
• Toshiyuki Kondo, Kazuki Hiramine, Hiroyuki Hirakata and Kohji Minoshima, "Fracture toughness of freestanding copper films with a thickness of 39 nm", Engineering Fracture Mechanics, Vol. 200 (2018), pp. 521-531. [Link]
• Hiroyuki Hirakata, Kousuke Shimbara, Toshiyuki Kondo and Kohji Minoshima, "Size effect on tensile creep behavior of micrometer-sized single-crystal gold", Materialia, Vol. 1 (2018), pp. 221-228. [Link]

2017

• Toshiyuki Kondo, Hiroyuki Hirakata and Kohji Minoshima, "Thickness effects on fatigue crack propagation in submicrometer-thick freestanding copper films", International Journal of Fatigue Vol. 103 (2017), pp. 444-455. [Link]

2016

• Hiroyuki Hirakata, Ryota Kotoge, Takumi Kameyama, Toshiyuki Kondo, Masayuki Sakihara and Kohji Minoshima, "Creep crack propagation behavior in submicron gold films", Procedia Structural Integrity, Vol. 2 (2016), pp. 1335-1342. [Link]
• Toshiyuki Kondo, Akihiro Shin, Hiroyuki Hirakata and Kohji Minoshima, "Fatigue crack propagation properties of submicron-thick freestanding copper films in vacuum environment", Procedia Structural Integrity, Vol. 2 (2016), pp. 1359-1366. [Link]
• Hiroyuki Hirakata, Takuya Yoshida, Toshiyuki Kondo and Kohji Minoshima, "Effects of film thickness on critical crack tip opening displacement in single-crystalline and polycrystalline submicron Cu films", Engineering Fracture Mechanics, Vol. 159 (2016), pp. 98-114. [Link]
• Hiroyuki Hirakata, Takumi Kameyama, Ryota Kotoge, Toshiyuki Kondo, Masayuki Sakihara and Kohji Minoshima, "Creep crack propagation in gold submicron films at room temperature", International Journal of Fracture, accepted for publication. [Link]

2015

• Toshiyuki Kondo, XiaoChen Bi, Hiroyuki Hirakata and Kohji Minoshima, "Mechanics of fatigue crack initiation in submicron-thick freestanding copper films", International Journal of Fatigue, Vol. 82 (2016), pp. 12-28. [Link]
• Toshiyuki Kondo, Takaki Ishii, Hiroyuki Hirakata and Kohji Minoshima, "Fatigue crack closure in submicron-thick freestanding copper films", Materials Science and Engineering: A, Vol. 643 (2015), pp. 96-108. [Link]
• Hiroyuki Hirakata, Yuki Takeda, Toshiyuki Kondo, and Kohji Minoshima, "Direct observation of the thickness effect on critical crack tip opening displacement in freestanding copper submicron-films by in situ electron microscopy fracture toughness testing", International Journal of Fracture, Vol. 192 (2015), pp. 203-216. [Link]
• Hiroyuki Hirakata, Kyosuke Takeuchi, and Kohji Minoshima, "Mechanics of fracture at nanoscale stress concentrated sites in titanium doglegged nanocolumn", Engineering Fracture Mechanics, Vol. 150 (2015), pp. 168-183. [Link]

2014

• Hiroyuki Hirakata, Takeshi Tagami and Kohji Minoshima, "Creep and Fracture of Structured Nanocolumns Grown on a Substrate", Procedia Materials Science, Vol. 3 (2014), pp. 385-390.[Link]
• Toshiyuki Kondo, Hiroyuki Hirakata, Masayuki Sakihara and Kohji Minoshima, "Characteristic Mechanism of Fatigue Crack Propagation in Submicron-thick Freestanding Copper Films", Procedia Materials Science, Vol. 3 (2014), pp. 544-549.[Link]
• Hiroyuki Hirakata, Yoshiaki Tsutsumi and Kohji Minoshima, "Creep fracture at interfaces of titanium nanocolumns on silicon substrate", Engineering Fracture Mechanics, Vol. 117 (2014), pp. 71-83. [Link]
• Hiroyuki Hirakata, Toshiyuki Kondo, Masayuki Sakihara and Kohji Minoshima, "Mechanics of fatigue crack propagation in submicron-thick freestanding copper films", Advanced Materials Research, Vols. 891-892 (2014), pp. 1681-1687.

2013

• Toshiyuki Kondo, Takahiro Imaoka, Hiroyuki Hirakata, Masayuki Sakihara and Kohji Minoshima, "Effects of stress ratio on fatigue crack propagation properties of submicron-thick free-standing copper films", Acta Materialia, Vol. 61 (2013), pp. 6310-6327. [Link]
• Hiroyuki Hirakata, Tomohiro Maruyama, Akio Yonezu, and Kohji Minoshima, "Creation of freestanding wrinkled nano-films with desired deformation properties by controlling the surface morphology of a sacrificial layer", Journal of Applied Physics, Vol.113 (2013), 203503. [Link]

2012

• Hiroyuki Hirakata, Naomichi Fukuhara, Shoichi Ajioka, Akio Yonezu, Masayuki Sakihara and Kohji Minoshima, "Thickness effect on steady state creep properties of freestanding aluminum nano-films", Acta Materialia,Vol. 60 (2012), pp. 4438-4447. [Link]
• Do Van Truong, Hiroyuki Hirakata, Takayuki Kitamura, Vuonga Van Thanh, Lea Van Lich, "Evaluation of interfacial toughness curve of bimaterial in submicron scale", International Journal of Solids and Structures, Vol. 49 (2012), pp. 1676-1684. [Link]
• Hiroyuki Hirakata, Yoshifumi Ajioka, Akio Yonezu and Kohji Minoshima, "Fabrication and Mechanical Properties of Column-Particle Nanocomposites by Multiscale Shape-Assisted Self-Assembly", Journal of Physics D: Applied Physics, Vol. 45 (2012), 025302. [Link]
• Akio Yonezu, Takuma Hara, Toshiyuki Kondo, Hiroyuki Hirakata and Kohji Minoshima, "Evaluation of Threshold Stress Intensity Factor of Hydrogen Embrittlement Cracking by Indentation Testing", Materials Science and Engineering A, Vol. 531 (2012), pp. 147-154. [Link]

2011

• Hiroyuki Hirakata, Osamu Nishijima, Naomichi Fukuhara, Toshiyuki Kondo, Akio Yonezu and Kohji Minoshima, "Size effect on fracture toughness of freestanding copper nano-films", Materials Science and Engineering A, Vol. 528 (2011), pp. 8120-8127. [Link]
• Hiroyuki Hirakata, Taku Nishihira, Akio Yonezu and Kohji Minoshima，"Frictional anisotropy of oblique nanocolumn arrays grown by glancing angle deposition", Tribology Letters, Vol.44 (2011), pp. 259-268. [Link]
• Hiroyuki Hirakata, Taku Nishihira, Akio Yonezu and Kohji Minoshima, "Interface strength of structured nanocolumns grown by glancing angle deposition", Engineering Fracture Mechanics, Vol.78 (2011), pp. 2800-2808. [Link]
• Masanori Nakatani, Hiroaki Fujihara, Masayuki Sakihara and Kohji Minoshima, "Fatigue crack growth acceleration caused by irreversible hydrogen desorption in high-strength steel and its mechanical condition", Materials Science and Engineering A, Vol. 528, pp. 7729-7738 (2011). [Link]
• Masanori Nakatani, Hiroaki Fujihara, Masayuki Sakihara and Kohji Minoshima, "Influence of irreversible hydrogen and stress cycle frequency on fatigue crack growth property in high-strength steel and hydrogen visualization", Procedia Engineering, Vol. 10, pp. 2381-2386 (2011). [Link]
• Masanori Nakatani, Hiroaki Fujihara, Masayuki Sakihara and Kohji Minoshima, "Influence of irreversible hydrogen and stress cycle frequency on fatigue crack growth property in high-strength steel and hydrogen visualization", Procedia Engineering, Vol. 10, pp. 2381-2386 (2011). [Link]
• Masanori Nakatani and Kohji Minoshima, "Influence of activation energy and sensitivity to hydrogen embrittlement on fatigue strength degradation by irreversible hydrogen in high-strength steels", Fatigue and Fracture of Engineering Materials and Structures, Vol. 34, pp. 363-373 (2011). [Link]
• Masanori Nakatani, Kohji Minoshima, "Fatigue Strength Degradation by Irreversible Hydrogen in Cold Drawn Eutectoid Steels", Key Engineering Materials, Volumes 462 - 463, pp.188-193, (2011) [Link]
• Tomohiro Maruyama, Hiroyuki Hirakata, Akio Yonezu and Kohji Minoshima, "Realization of freestanding wrinkled thin films with flexible deformability" Applied Physics Letters, 98, 041908, (2011) [Link]
• Takayuki Kitamura, Hiroyuki Hirakata, Takahiro Shimada and Takashi Sumigawa, Fracture Nanomechanics, Pan Stanford Publishing, ISBN: 978-9814241830, 2011[Link]

2010

• Akio Yonezu, Keishi Yoneda, Hiroyuki Hirakata, Masayuki Sakihara and Kohji Minoshima, "A Simple Method to Evaluate Anisotropic Plastic Properties Based on Dimensionless Function of Single Spherical Indentation - Application to SiC Whisker Reinforced Aluminum Alloy -", Materials Science and Engineering A,Vol.527, pp.7646–7657 (2010) [Link]
• Hiroyuki Hirakata, Kenji Ito, Akio Yonezu, Hiroaki Tsuchiya, Shinji Fujimoto and Kohji Minoshima, "Strength of Self-organized TiO₂ Nanotube Arrays", Acta Materialia,Vol.58 pp.4956–4967 (2010). [Link]
• Hiroyuki Hirakata, Hiroki Ogiwara, Akio Yonezu, Kohji Minoshima, "Evaluation of Incipient Plasticity from Interfaces between Ultra-thin Gold Films and Compliant Substrates", Thin Solid Films, Vol.518, pp.5249–5256 (2010) [Link]
• Hiroyuki Hirakata, Takeshi Yamada, Yoshiki Nobuhara, Akio Yonezu and Kohji Minoshima, "Hydrogen Effect on Fracture Toughness of Thin Film/Substrate Interfaces", Engineering Fracture Mechanics, Vol.77, pp. 803–818 (2010) [Link]
• Akio Yonezu, Masanori Arino, Toshiyuki Kondo, Hiroyuki Hirakata, and Kohji Minoshima, "On Hydrogen-induced Vickers Indentation Cracking in High-strength Steel", Mechanics Research Communications, Vol.37, pp.230–234 (2010) [Link]
• Keishi Yoneda, Akio Yonezu, Hiroyuki Hirakata and Kohji Minoshima, "An Estimation of Anisotropic Plastic Property of Engineering Steels from Spherical Impressions", International Journal of Applied Mechanics, Vol.2, No. 2, pp.355–379 (2010). [Link]

2009

• Akio Yonezu, Yoshiki Kuwahara, Keishi Yoneda, Hiroyuki Hirakata and Kohji Minoshima, "Estimation of the Anisotropic Plastic Property using Single Spherical Indentation -An FEM Study", Computational Materials Science, Vol.47,　pp.611- 619 (2009)  [Link]

2008

• Yoshimasa TAKAHASHI, Hiroyuki HIRAKATA and Takayuki KITAMURA, “Experimental Evaluation of Plastic Property of A Low-Dimensional Cu Nano-Component”, Materials Science Forum, Vols. 567-568 (2008), pp. 297-300.
• Yoshimasa TAKAHASHI, Hiroyuki HIRAKATA and Takayuki KITAMURA, “Quantitative Evaluation of Plasticity of A Ductile Nano-Component”, Thin Solid Films, Vol. 516 (2008), pp. 1925-1930.
• Kittikorn NGAMPUNGPIS, Takayuki KITAMURA and Hiroyuki HIRAKATA, “Increase of Stress Intensity near Interface Edge of Elastic-Creep Bi-Material under A Sustained Load”, Engineering Fracture Mechanics, Vol. 75 (2008), pp. 1285-1293.
• Hiroyuki HIRAKATA, Toshihiro HIRAKO, Yoshimasa TAKAHASHI, Yasunori MATSUOKA and Takayuki KITAMURA ,“Creep Crack Initiation at A Free Edge of An Interface between Submicron Thick Elements”, Engineering Fracture Mechanics, Vol. 75 (2008), pp. 2907-2920.
• Takashi SUMIGAWA, Hiroyuki HIRAKATA, Masaki TAKEMURA, Shohei MATSUMOTO, Motofumi SUZUKI and Takayuki KITAMURA, “Disappearance of Stress Singularity At Interface Edge Due to Nanostructured Thin Film”,Engineering Fracture Mechanics, Vol. 75 (2008), pp. 3073-3083.
• Kohji MINOSHIMA, Masanori NAKATANI, Atsushi SUGETA and Masayuki SAKIHARA, "Influence of Irreversible Hydrogen on the Fatigue Strength in Cold Drawn High Strength Steel", Journal of Solid Mechanics and Mechanical Engineering，Vol. 2, No. 11 (2008), pp. 1436-1443. [Link]

2007

• K. Tanaka, K. Minoshima, T. Imoto,"Young's modulus of polysilicon thin film evaluated by finite element analysis" , Key Engineering Materials, Vol. 353-358, Part 3 (2007), pp.  2227-2230.
• Hiroyuki HIRAKATA, Shohei MATSUMOTO, Masaki TAKEMURA, Motofumi SUZUKI and Takayuki KITAMURA ,“Anisotropic　Deformation of　Thin Films Comprised of Helical Nanosprings”, International Journal of Solids and Structures, Vol. 44 (2007), pp. 4030-4038.
• Takayuki KITAMURA, Hiroyuki HIRAKATA, and Do Van TRUONG, “Initiation of Interface Crack at Free Edge between Thin Films with　Weak Stress Singularity”, Thin Solid Films, Vol. 515 (2007), pp. 3005-3010.
• Takayuki KITAMURA, Kittikorn NGAMPUNGPIS and Hiroyuki HIRAKATA ,"Stress Field near Interface Edge of Elastic-Creep Bi-Materia", Engineering Fracture Mechanics, Vol. 74 (2007), pp. 1637-1648.
• Kittikorn NGAMPUNGPIS, Hiroyuki HIRAKATA and Takayuki KITAMURA, “Increase of Stress Intensity near Free-Edge of Elastic-Creeping Bi-Material Interface under A Sustained Load”, Key Engineering Materials, Vols. 340-341 (2007), pp. 501-506.
• Takayuki KITAMURA, Hiroyuki HIRAKATA and Yoshimasa TAKAHASHI, "Interface Strength of Low-Dimensional Nano-Components",Key Engineering Materials, Vols. 353-358 (2007), pp. 1-8.
• Kittikorn NGAMPUNGPIS, Takayuki KITAMURA and Hiroyuki HIRAKATA ,“Effect of Material Thickness on The Singular Stress Field in Elastic-Creep Bi-Material Interface”, Journal of Solid Mechanics and Materials Engineering, Vol. 1, No. 6 (2007), pp. 744-754.
• Hiroyuki HIRAKATA, Yoshimasa TAKAHASHI, Do Van TRUONG and Takayuki KITAMURA ,"Role of Plasticity on Interface Crack　Initiation at Free Edge and Its Propagation in Nanostructures", International Journal of Fracture, Vol. 145 (2007), pp. 261-271.
• Akio Yonezu, Hiroyuki Hirakata, Kohji Minoshima, "An Algorithm to Determine Plastic Properties of Metals Based on Loading Data in Single Sharp Indentation", Fundamentals of Nanoindentation and Nanotribology IV, (edited by EL Bourhis, DJ Morris, L Michelle, OR Schwaiger and T Staedler), Materials Research Society Symposium Proceeding, Volume 1049, AA05-03, 2007.

2006

• K. Tanaka, K. Minoshima, H. Yamada, " Measurement of the fiber stress distribution during pull-out test by means of micro-Raman spectroscopy and FEM analysis", WIT Transactions on the Built Environment, Vol. 85 (2006), pp. 131-139.
• Hiroyuki HIRAKATA, Masaya KITAZAWA and Takayuki KITAMURA ,“Fatigue Crack Growth along Interface between Metal and Ceramics Submicron-Thick Films in Inert Environment” , Acta Materialia, Vol. 54 (2006), pp. 89-97.
• Hiroyuki HIRAKATA, Yoshimasa TAKAHASHI, Shohei MATSUMOTO and Takayuki KITAMURA ,“Dominant Stress Region for Crack Initiation at Interface Edge of Microdot on A Substrate”, Engineering Fracture Mechanics, Vol. 73 (2006), pp. 2698-2709.
• Do Van TRUONG, Hiroyuki HIRAKATA and Takayuki KITAMURA, "Effect of Loading Frequency onFatigue Crack Growth between A Submicron-Thick Film and A Substrate", JSME Internatinal Journal Series A,Vol. 49 (2006), No. 3, pp. 370-375.

2005

• K. Minoshima, Y. Oie, and K. Komai,  "Nanoscopic fatigue and stress corrosion crack growth behaviour in a high-strength stainless steel visualized in situ by atomic force microscopy", Fatigue & Fracture of Engineering Materials and Structures, Vol. 28, No. 11 (2005), pp. 951-961.
• Hiroyuki HIRAKATA, Takayuki KITAMURA and Takato KUSANO ,“Pre-cracking Technique for Fracture Mechanics Experiment along Interface between Thin Film and Substrate” ,Engineering Fracture Mechanics, Vol. 72 (2005), pp. 1892-1904.
• Fulin SHANG, Takayuki KITAMURA, Hiroyuki HIRAKATA, Isaku KANNO, Hidetoshi KOTERA and Kenichiro TERADA, "Experimental and Theretical Investigations of Delamination at Free Edge of Interface between Piezoelectric Thin Films on a Substrate",International Journal of Solids and Structures, Vol. 42 (2005), pp. 1729-1741.
• Fulin SHANG, Takayuki KITAMURA and Hiroyuki HIRAKATA ,“Delamination Test and The Effect of Free Edge on Interface Strength of PZT Thin Films” ,Integrated Ferroelectrics, Vol. 73 (2005), pp. 67-74.