Faculty Profiles - YOSHIMURA Akinori

Papers - YOSHIMURA Akinori

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Numerical investigation of damage propagation of woven composite using decoupled multi-scale method Reviewed

C. Hoshikawa, A. Yoshimura, K. Goto, M. Arai

Mechanical Engineering Journal Vol. 11 ( 4 ) page： 24-00012 2024.8

Identification of interfacial strength between carbon fiber and epoxy matrix in CFRP laminates using pulse laser spallation method Reviewed

M. Arai, R. Nakamura, H. Katayama, K. Goto, A. Yoshimura, H. Ito

Advanced Composite Materials Vol. 34 ( 2 ) page： 220 - 228 2024.7

Fracture mechanism of carbon fiber-reinforced thermoplastic composite laminates under compression after impact Invited Reviewed

Journal of Composite Materials page： Accepted 2024.3

面外引張／せん断組合せ応力試験によるクロスプライCFRP積層板の層間強度評価 Invited Reviewed

榎本匠, 後藤圭太, 荒井政大, 吉村彰記

日本複合材料学会誌 Vol. 49 ( 6 ) page： 183 - 190 2023.11

CFRP内ボイドがTalbot-Lau干渉計暗視野画像に及ぼす影響 Invited Reviewed

浅野圭亮, 吉村彰記, 荒井政大, 後藤圭太, 有本直

日本複合材料学会誌 Vol. 49 ( 6 ) page： 199 - 207 2023.11

Experimental Evaluation of Fatigue Properties of Carbon Fiber/Epoxy Matrix Interface and Numerical Simulation of Transverse Cracking under Cyclic Load Reviewed

Y. Kitagawa, K. Sasaki, M. Arai, A. Yoshimura, K. Goto

Advanced Composite Materials Vol. 33 ( 2 ) page： 212 - 232 2023.6

極低温におけるCFRP サンドイッチ構造発泡コアの引張特性 Reviewed

小林充, 吉村彰記, 後藤圭太, 荒井政大

日本複合材料学会誌 Vol. 49 ( 3 ) page： 75 - 81 2023.5

In situ optical observation of damage and failure process in adhesively bonded CFRP joints under mixed-mode loading Reviewed

S. Oshima, T. Mikami, A. Yoshimura, Y. Hirano, T. Ogasawara

Composite Structures Vol. 305 page： 116453 2023.2

内部構造を考慮した非連続CFRTPのマルチスケール解析 Reviewed

後藤圭太，宮島雅治, 小林嶺太, 荒井政大, 吉村彰記

日本複合材料学会誌 Vol. 48 ( 5 ) page： 201 - 210 2022.11

Prediction of transverse crack multiplication of CFRP cross-ply laminates under tension-tension fatigue load Reviewed

Y. Kitagawa, M. Arai, A. Yoshimura, K. Goto

Advanced Composite Materials Vol. 32 ( 3 ) page： 419 - 436 2022.8

Impact penetration test and residual tensile strength of CFRP Reviewed

Vol. 88 ( 910 ) page： 1 - 13 2022.6

Performance assessment for fiber tracking of unidirectional carbon fiber reinforced plastic by digital image correlation of X-ray computed-tomography Reviewed

S. Morita, M. Ueda, T. Takahashi, K. Kajiwara, A. Yoshimura, N. Sugiura

Advanced Composite Materials Vol. 32 ( 1 ) page： 35 - 47 2022.5

Experimental and numerical evaluation of effects of kidney-shape carbon fiber on transverse cracking of carbon fiber reinforced plastics Invited Reviewed

Y. Kitagawa, A. Yoshimura, M. Arai, K. Goto, N. Sugiura

Composites Part A Vol. 152 page： 106690 2021.10

Inverse analysis of interlaminar strength in CFRP laminates using pulse laser spallation method Reviewed

M. Arai, T. Chiba, K. Goto, A. Yoshimura

Composites Science and Technology Vol. 241 page： 108938 2021.7

Mechanical Properties of CFRP Foam Core Sandwich Structure at Cryogenic Temperature Reviewed

Vol. 47 ( 4 ) page： 150 - 158 2021.7

Suppression of the Out-of-Plane Thermal Deformation of CFRP Laminate due to Fiber Orientation Error by Stacking Sequence Optimization Reviewed

Vol. 47 ( 4 ) page： 159 - 167 2021.7

Effect of material nonlinearity on the toughness evaluation in quasi-static mode II interlaminar fracture toughness tests of composite laminates Reviewed

S. Yashiro, T. Yamasaki, H. Nagai, A. Yoshimura

Engineering Fracture Mechanics Vol. 253 page： 107879 2021.7

Relation between Dark-field Images Derived using X-Ray Talbot-Lau Interferometer and Carbon Fiber Distribution in CFRP Reviewed

Y. Kasai, A. Yoshimura, M. Arai, K. Goto, A. Yamanaka, H. Shindo

Advanced Composite Materials Vol. 30 ( 6 ) page： 591 - 604 2021.4

Experimental and numerical study on progressive damage and failure in composite laminates during open-hole compression tests Reviewed

R. Higuchi, S. Warabi, A. Yoshimura, T. Nagashima, T. Yokozeki, T. Okabe

Composites Part A Vol. 145 page： 106300 2021.3

Relationship between Dark-field Image Derived by X-Ray Talbot-Lau Interferometer and Carbon Fiber Distribution in CFRP Reviewed

Vol. 47 ( 1 ) page： 11-19 2021.1

High-speed observation of bending fracture process of carbon fiber reinforced plastic composite/NomexTM honeycomb sandwich panel Reviewed

T. Ogasawara, H. Yoshinaga, M. Oiwa, T. Oguri, T. Matsuda, H. Kusano, A. Yoshimura

Journal of Sandwich Structures and Materials Vol. 23 ( 6 ) page： 1987 - 1999 2020.2

Experimental and analytical validation of mode II fracture toughness tests for a type of double-lap joint Reviewed

S. Oshima, A. Yoshimura, S. Yashiro, Y. Hirano, T. Ogasawara

Composite Structures Vol. 234 page： 111757 2020.2

In-situ observation of microscopic damage in adhesively bonded CFRP joints under mode I and mode II loading Reviewed

S. Oshima, A. Yoshimura, Y. Hirano, T. Ogasawara, Kwek-Tze Tan

Composite Structures Vol. 227 2019.8

Simulation on kink-band formation during axial compression of a unidirectional carbon fiber-reinforced plastic constructed by X-ray computed tomography images

T. Takahashi, M. Ueda, K. Iizuka, A. Yoshimura, T. Yokozeki

Advanced Composite Materials Vol. 28 ( 4 ) page： 347-363 2019.7

Simulation on Kink-band Formation during Axial Compression of a Unidirectional Carbon Fiber Reinforced Plastic Constructed by X-ray Computed Tomography Images Reviewed

Vol. 45 ( 2 ) page： 52-60 2019.3

Development of a three-dimensional finite element model for a unidirectional carbon fiber reinforced plastic based on X-ray computed tomography images and the numerical simulation on compression Reviewed

K. Iizuka, M. Ueda, T. Takahashi, A. Yoshimura, M. Nakayama

Advanced Composite Materials Vol. 28 ( 1 ) page： 73-85 - 85 2019.1

A Numerical simulation of delamination caused by internal gas pressure for mid-density CFRP Reviewed

J. Koyanagi, K. Shinba, Y. Fukuda, K. Hirai, A. Nakazato, A. Yoshimura, T. Aoki and Y. Kogo

Composites Part A: Applied Science and Manufacturing Vol. 115 page： 255-263 2018.12

High fidelity simulation of low velocity impact behavior of CFRP laminate Reviewed

Ebina Masaya, Yoshimura Akinori, Sakaue Kenichi, Waas Anthony M.

COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING Vol. 113 page： 166-179 2018.10

Experimental method for mode I fracture toughness of composite laminates using wedge loaded double cantilever beam specimens Reviewed

S. Oshima, A. Yoshimura, Y. Hirano, T. Ogasawara

Composites Part A: Applied Science and Manufacturing Vol. 112 page： 119-125 2018.9

A new approach for evaluating crack growth resistance curve of mode II delamination by doubly end-notched tension tests Reviewed

S. Yashiro, T. Agata, A. Yoshimura

Advanced Composite Materials Vol. 27 ( 2 ) page： 119-133 2018.3

New Test Method for Mode II Interlaminar Fracture Toughness of Composite Laminates: Doubly End Notched Tension Method Reviewed

S. Yashiro, T. Agata, A. Yoshimura

Journal of the Japan Society for Composite Materials Vol. 44 ( 1 ) page： 19-24 2018.1

Progressive failure under high-velocity impact on composite laminates: Experiment and phenomenological mesomodeling Reviewed

R. Higuchi, T. Okabe, A. Yoshimura, T.E. Tay

Engineering Fracture Mechanics Vol. 178 page： 346-361 2017.6

Fracture toughness of CFRP adhesive bonded joint under cryogenic temperature Reviewed

A. Yoshimura

Zairyo/Journal of the Society of Materials Science, Japan Vol. 66 ( 4 ) page： 282-287 2017.4

Local out-of-plane deformation of CFRP ablator subjected to rapid heating Reviewed

J. Koyanagi, Y. Fukuda, S. Yoneyama, K. Hirai, A. Yoshimura, T. Aoki, T. Ogasawara

Advanced Composite Materials Vol. 26 ( 1 ) page： 23-34 2017.1

Development of a Three-dimensional Finite Element Model for a Unidirectional Carbon Fiber Reinforced Plastic Based on X-ray Computed Tomography Images and the Numerical Simulation on Compression Reviewed

IIZUKA Keisuke, UEDA Masahito, TAKAHASHI Takuya, YOSHIMURA Akinori, NAKAYAMA Masahiro

Journal of the Japan Society for Composite Materials Vol. 43 ( 6 ) page： 219-225 2017

Language：Japanese Publishing type：Research paper (scientific journal)

<p>A unidirectional carbon fiber reinforced plastic (CFRP) was scanned by an X-ray computed tomography (CT) system. Based on the X-ray CT images, a three-dimensional model with random fiber waviness was developed. Each fiber location was identified in a sectional CT image. Subsequently, the relative displacement of fibers between adjacent sectional CT images was obtained with a digital image correlation method. This procedure was repeated to obtain fiber waviness along the axial direction. The constructed three-dimensional fiber model showed random waviness of each fiber in the unidirectional CFRP. Finite element analysis was performed using the three-dimensional model. Simulation results showed bending and twisting deformations coupled with axial contractions during axial compression, which developed due to fiber waviness. A reduction of the axial Young's modulus due to fiber random waviness was quantitatively evaluated.</p>

DOI： 10.6089/jscm.43.219

Flight demonstration of Electric Aircraft Technology for Harmonized Ecological Revolution (FEATHER)

NISHIZAWA Akira, OKAI Keiichi, KOBAYASHI Hiroshi, IIJIMA Tomoko, YAMAZAKI Kohji, OKUYAMA Masahiro, TAGASHIRA Takeshi, HIRANO Yoshiyasu, YOSHIMURA Akinori, SHINDO Shigemi

Aeronautical and Space Sciences Japan Vol. 65 ( 7 ) page： 8-12 2017

Application of Additive Manufacturing Technology for Micro-Lattice Structure Reviewed

Vol. 6 ( 3 ) page： 125-129 2017

先進複合材料の研究開発におけるX線CTの適用とその可能性 Reviewed

吉村　彰記

非破壊検査 Vol. 66 ( 7 ) page： 289-294 2017

Multiscale homogenization for nearly periodic structures Reviewed

A. Yoshimura, A. M. Waas

Composite Structures Vol. 153 page： 345-355 2016.10

Structural optimization for CFRP cryogenic tank based on energy release rate Reviewed

H. Fukui, A. Yoshimura, R. Matsuzaki

Composite Structures Vol. 152 page： 883-890 2016.9

X-ray computed tomography used to measure fiber orientation in CFRP laminates Reviewed

A. Yoshimura, R. Hosoya, J. Koyanagi, T. Ogasawara

Advanced Composite Materials Vol. 25 ( 1 ) page： 19-30 2016.1

Local Out-of-Plane Deformation of CFRP Ablator Subjected to Rapid Heating Reviewed

KOYANAGI Jun, FUKUDA Yasuhiro, YONEYAMA Satoru, HIRAI Ken-ichi, YOSHIMURA Akinori, AOKI Takuya, OGASAWARA Toshio

Journal of the Japan Society for Composite Materials Vol. 42 ( 4 ) page： 146-152 - 152 2016

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Society for Composite Materials

Local out-of-plane deformation of CFRP ablator subjected to very rapid heating was investigated in this study. The local out-of-plane deformation is measured by three dimensional digital image correlation (3D-DIC) technique. The 3D-DIC at high temperature is achieved by high-temperature resistance random pattern on specimen surface using ceramic bond and blue filter intended for cutting strong infrared radiation from the specimen. Then discussed the mechanism of the local out-of-plane deformation only at the rapid heating condition, in terms of carbonization, pyrolysis gas occurrence, gas pressure storage and interlaminar debonding due to the gas pressure in this study.

DOI： 10.6089/jscm.42.146

Further investigation of Delamination Reduction Trend for stitched composites Reviewed

Tan K. T., Yoshimura A., Watanabe N., Iwahori Y., Ishikawa T.

COMPOSITES SCIENCE AND TECHNOLOGY Vol. 118 page： 141-153 2015.10

Damage simulation of stitched CFRP laminates under high-velocity projectile impact Reviewed

Akinori Yoshimura, Yasuhito Mikami, Masahiro Nakayama, Toshio Ogasawara, Naoyuki Watanabe

ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) Vol. 1-2015 2015

Language：English Publishing type：Research paper (international conference proceedings) Publisher：American Society of Mechanical Engineers (ASME)

In this study, numerical analytical model which simulates the damage behavior of the through-the-thickness stitched CFRP laminates under high velocity impact (HVI) is developed. The simulation results are compared with experimental results for validation of the developed model. Through-the-thickness stitched CFRP laminates have good mechanical properties such as higher delamination toughness and better impact resistance than that of conventional laminates. In this study, rigid body impact tests were conducted for the stitched CFRP laminates. Test results revealed that through-the-thickness stitching effectively suppressed the propagation of the delamination, and it increased the performance against the perforation. Among them, moderate stitched CFRP had the highest performance. In order to analyze the HVI damage behavior of the stitched CFRP laminate, special finite element model was developed. In the model, the in-plane tensile and compressive fiber damages were considered by using stress criterion. Transverse cracks were modeled by continuum damage mechanics (CDM). Delamination was modeled by cohesive zone model (CZM). The effect of the stitch threads were introduced by multiscale approach. Out-of-plane tensile tests were performed for small specimens those include single stitching. Small finite element model which contains a non-linear spring element was prepared, and the load-displacement relationship of the nonlinear spring was decided so that the result of the model agreed with the tests. Then, the spring elements were introduced to the HVI simulation model. The simulation results revealed that stitching bridges the delamination and delamination area was reduced. On the other hand, the simulation results revealed that delamination reduces the tensile stress in the bottom surface of the laminate. Because delamination easily propagate in the moderate stitched laminates, the performance against the perforation of the moderate stitched laminates is the highest among the stitched laminates.

DOI： 10.1115/IMECE2015-52467

Scopus

電動モータグライダシステムのモータマウント強度試験

吉村彰記, 平野義鎭, 西沢啓

JAXA research and development memorandum Vol. 14 ( 007 ) page： 1-24 2015

Titanium alloy foil-inserted carbon fiber/epoxy composites for cryogenic propellant tank application Reviewed

T. Ogasawara, N. Arai, R. Fukumoto, T. Ogawa, T. Yokozeki, A. Yoshimura

Advanced Composite Materials Vol. 23 ( 2 ) page： 129-149 2014.3

Evaluation of Spaceborne SiC Mirror Materials Using Samples Cut from the Periphery of a Mirror Body Reviewed

Kotani Masaki, Muta Yoshikazu, Yoshimura Akinori, Ogihara Shinji, Imai Tadashi, Katayama Haruyoshi, Yui Yukari, Tange Yoshio, Enya Keigo, Kaneda Hidehiro, Nakagawa Takao

JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE Vol. 23 ( 3 ) page： 850-858 2014.3

Characterization of high-velocity impact damage in CFRP laminates: Part II - Prediction by smoothed particle hydrodynamics Reviewed

Shigeki Yashiro, Keiji Ogi, Akinori Yoshimura, Yoshihisa Sakaida

Composites Part A: Applied Science and Manufacturing Vol. 56 page： 308 - 318 2014

Language：English Publishing type：Research paper (scientific journal)

High-velocity impact damage in CFRP laminates was studied experimentally and numerically. Part I of this study observed and evaluated near-perforation damage in the laminates and characterized the damage pattern experimentally. Part II predicts the extension of high-velocity impact damage based on smoothed particle hydrodynamics (SPH), which facilitates the analysis of large deformations, contact, and separation of objects. A cross-ply laminate was divided into 0 and 90 layers, and virtual interlayer particles were inserted to express delamination. The damage patterns predicted on the surfaces and cross-sections agreed well with the experiments. The analyzed delamination shape was similar to that resulting from a low-velocity impact, consisting of pairs of fan-shaped delaminations symmetric about the impact point. Finally, the mechanisms of high-velocity impact damage in CFRP laminates are discussed based on the observations and numerical analyses. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.compositesa.2013.04.012

Scopus

Measurement of Fiber Orientation in CFRP Laminates by Using X-ray Computed Tomography Reviewed

YOSHIMURA Akinori, HOSOYA Ryohei, KOYANAGI Jun, OGASAWARA Toshio

Journal of the Japan Society for Composite Materials Vol. 40 ( 4 ) page： 146-152 2014

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

In this paper a new method which measures fiber orientation in CFRP laminates from X-ray CT images is proposed. In the proposed method, fiber orientation is analyzed by applying digital image correlation method (DIC) to the acquired tomographic images. By using DIC, brightness pattern, which results from radiodensity difference between fiber and resin, is compared between two different planes in thickness direction. Then three dimensional displacement of brightness pattern, which indicates fiber orientation, can be measured. In this study, we applied the proposed method to a quasi-isotropic CFRP laminate. After X-ray CT imaging, the sample was sectioned and polished. Fiber orientation was then experimentally measured by using a microscope. Fiber orientation calculated by the proposed method agrees very well with experimentally measured one, and the validity of the proposed method was demonstrated. Additionally, we applied the proposed method to a plane-woven CFRP laminate. The result revealed that the invalid fiber orientation may be calculated for the fiber orientation is parallel to the plane of CT image, or for the fiber orientation is calculated using the pattern around the outer edge of CT images.

DOI： 10.6089/jscm.40.146

Fracture Simulation of Adhesively-bonded Joint in Composite Structure

Vol. 50 ( 5 ) page： 179-184 2014

Effect of stitch density and stitch thread thickness on damage progression and failure characteristics of stitched composites under out-of-plane loading Reviewed

Tan K. T., Yoshimura A., Watanabe N., Iwahori Y., Ishikawa T.

COMPOSITES SCIENCE AND TECHNOLOGY Vol. 74 page： 194-204 2013.1

Development of High-Performance CFRP Flywheel Reviewed

KOYANAGI Jun, HOJO Masahiro, YOSHIMURA Akinori, YONEYAMA Satoru, SUSUKI Ippei

Journal of Solid Mechanics and Materials Engineering Vol. 7 ( 3 ) page： 426-438 2013

Characterization of high-velocity impact damage in CFRP laminates: Part i - Experiment Reviewed

Shigeki Yashiro, Keiji Ogi, Tsukasa Nakamura, Akinori Yoshimura

Composites Part A: Applied Science and Manufacturing Vol. 48 ( 1 ) page： 93 - 100 2013

Language：English Publishing type：Research paper (scientific journal)

This study investigated mechanisms of the extension of high-velocity impact damage in CFRP laminates. To this end, damage states due to near-perforation impact were studied in detail. This study consists of two parts. Part I presents the experiment results of high-velocity impact tests for CFRPs with specified stacking sequences. A crater and splits were observed on the impacted surface, while multiple splits with fiber breaks extended on the back surface. The cross-section beneath the impact point included catastrophic ply failure with extensive fiber breaks. Impacted specimens also exhibited a particular delamination pattern consisting of pairs of symmetric fan-shaped delaminations emanating from to the impact point and elongated delamination along the cracks in the bottom ply. These damage patterns were common to all of the stacking sequences. Part II of this study presents a numerical analysis of high-velocity impact based on smoothed-particle hydrodynamics and discusses damage extension mechanisms. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.compositesa.2012.12.015

Scopus

液体窒素浸漬試験による複合材料製極低温推進剤タンクの熱応力軽減設計の検証

吉村彰記, 小笠原俊夫, 末益博志

JAXA research and development memorandum Vol. 12 ( 012 ) page： 1-12 2013

Interlaminar fracture toughness of 5 harness satin woven fabric carbon fiber/epoxy composites Reviewed

[36] T. Ogasawara, A. Yoshimura, T. Ishikawa, R. Takahashi, N. Sasaki, T. Ogawa

Advanced Composite Materials Vol. 21 ( 1 ) page： 45-56 2012.10

Fracture toughness of CFRP adhesive bonded joints at cryogenic temperature Reviewed

A. Yoshimura, T. Takaki, Y. Noji, T. Yokozeki, T. Ogasawara, S. Ogihara

Journal of Adhesion Science and Technology Vol. 26 ( 7 ) page： 1017-1031 2012.4

Effect of fiber arrangement on shape fixity and shape recovery in thermally activated shape memory polymer-based composites Reviewed

M. Nishikawa, K. Wakatsuki, A. Yoshimura, N. Takeda

Composites Part A: Applied Science and Manufacturing Vol. 43 ( 1 ) page： 165-173 2012.1

Damage Analysis of CFRP Laminates under the Soft-Body Impact Reviewed

KOMAGATA Daisuke, OKABE Tomonaga, YASHIRO Shigeki, YOSHIMURA Akinori, OGASAWARA Toshio

Journal of the Japan Society for Composite Materials Vol. 37 ( 5 ) page： 164-171 2011.9

Language：Japanese Publishing type：Research paper (scientific journal)

The application of composite laminates to fan blade of turbofan engine is demanded in order to reduce the fuel cost and the noise of aircrafts. Bird strike is one of the most important problems in the engineering application of fan blades. However, the soft-body impact damage on the composite laminates under high-velocity impact has not been clarified sufficiently due to their complexity. Therefore, it is necessary to understand the damage process of the composite materials under the soft-body impact. The current work presented the numerical simulation for soft-body impact using the SPH method to address the large deformation problem, and discussed the change of the failure mode of the composite laminates as a function of impact velocity. Especially, in order to simulate the realistic damage process in composite laminates, a novel approach for the separation of particles was introduced to the model. We confirmed that the numerical simulation was applicable in the soft-body impact problem by the agreement of contact pressure with the experimental results. Moreover, it was shown that the catastrophic failure of the composite laminates by the soft-body impact could be also predicted using this numerical simulation.

DOI： 10.6089/jscm.37.164

Three-dimensional measurement of CFRP deformation during high-speed impact loading Reviewed

Yamada Masayoshi, Tanabe Yasuhiro, Yoshimura Akinori, Ogasawara Toshio

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT Vol. 646 ( 1 ) page： 219-226 2011.8

Mode II Fracture Toughness of CFRP Adhesive Bonded Structure at Cryogenic Temperature Reviewed

YOSHIMURA Akinori, NOJI Yohei, OGASAWARA Toshio, YOKOZEKI Tomohiro, OGIHARA Shinji

Journal of the Japan Society for Composite Materials Vol. 37 ( 4 ) page： 130-137 2011.7

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

In the present paper, end notched flexure (ENF) tests are conducted for CFRP/CFRP, CFRP/aluminum sheet adhesive bonded specimens at room temperature (296 K), at low temperature (223 K) and at cryogenic temperature (77 K) in order to investigate the mode II adhesive fracture toughnesses. Large difference of the coefficients of thermal expansion (CTE) between the CFRP and the aluminum sheet derives considerable thermal stress at the cryogenic temperature. Therefore, in the ENF tests, the effect of thermal stress must be considered. In the present paper, first the effect of thermal deformation is analytically discussed, and ENF tests are then carried out. The test results reveal that the fracture toughness is much higher at the low temperature than at the room temperature. However, the toughness is significantly lower at the cryogenic temperature than at the low temperature. Moreover, the results show that the crack extends in the adhesive film (cohesive failure) at the room and the low temperatures, whereas it extends at the interface between adhesive film and CFRP (adhesive failure) at the cryogenic. These results imply that the transition of the crack surface caused the degraded adhesive fracture toughness.

DOI： 10.6089/jscm.37.130

High-Velocity Impact Damage in CFRP Unidirectional and Cross-Ply Laminates Reviewed

OGI Keiji, TANAKA Takaaki, YASHIRO Shigeki, YOSHIMURA Akinori

Journal of the Society of Materials Science, Japan Vol. 60 ( 5 ) page： 418-424 2011

Language：Japanese Publishing type：Research paper (scientific journal)

This paper aims at characterizing the high-velocity impact damage behavior in carbon fiber reinforced plastic (CFRP) unidirectional (UD) and cross-ply (CP) laminates. First, the surface and internal damages of CFRP plates impacted at a velocity of 200 and 430m/s were observed by using optical microscopy together with radiography. Next, dynamic finite element analysis was performed to simulate the damage process. Cohesive elements were introduced to express the delamination and splitting cracks while the maximum stress fracture criteria were employed to express the intralaminar failure. Finally, the simulations were compared with the experiment results to verify the reasonability of the analysis. The damage process in both laminates was as follows : 1. A crater accompanied by splitting cracks is generated at the impact point on the front surface while splitting cracks due to bending are observed on the back surface. 2. Cone-shaped matrix cracking is observed in the UD laminate while few matrix cracking is generated in the CP laminate. 3. The shape of the delamination in the UD and CP laminates is a galaxy and a circle, respectively. Delamination size is larger in the CP laminate than in the UD laminate, which results in higher energy absorption capability in the CP laminate. Simulations are in qualitatively good agreement with the experiment results.

DOI： 10.2472/jsms.60.418

Damage Growth Analysis in Particle-Reinforced Composite Using Cohesive Element Reviewed

Akinori Yoshimura, Tomonaga Okabe

ADVANCED COMPOSITE MATERIALS Vol. 20 ( 6 ) page： 569 - 583 2011

Language：English Publishing type：Research paper (scientific journal) Publisher：VSP BV

In this paper, a simple numerical analytical method is proposed for simulating crack extension in a particulate-reinforced composite material. The numerical method is based on finite element analysis with the homogenization method, where crack extension is expressed using embedded cohesive elements. We first present the formulation of the numerical model and verify the model's validity by comparing the simulated crack extension with the linear fracture mechanics. Next we simulate damage extension for a composite reinforced with spherical particles. We consider the cracks in the particles and on particle-matrix interfaces. The analytical results reveal the effect of crack extension on the macroscopic material properties of the composite. The particle crack extends unstably and sharply decreases the tangent modulus of the material, irrespective of the initial flaw size. In contrast, the interfacial crack invariably grows stably and decreases the tangent modulus gradually. (C) Koninklijke Brill NV, Leiden, 2011

DOI： 10.1163/156855111X610406

Web of Science

Scopus

平織CFRP積層板に加工されたネジ穴の引張り強さ

小笠原俊夫, 吉村彰記, 紙田徹

JAXA research and development memorandum Vol. 11 ( 002 ) page： 1-11 2011

Damage characterization in thin-ply composite laminates under out-of-plane transverse loadings Reviewed

Tomohiro Yokozeki, Akiko Kuroda, Akinori Yoshimura, Toshio Ogasawara, Takahira Aoki

COMPOSITE STRUCTURES Vol. 93 ( 1 ) page： 49 - 57 2010.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Composite laminates with thin-ply layers are expected to exhibit superior damage resistance to the standard composite laminates. This study investigated the damage characteristics of carbon fiber/toughened epoxy thin-ply laminates subjected to transverse loadings. Quasi-isotropic laminates were prepared using both standard prepregs and thin-ply prepregs in order to examine the effect of ply thickness on the damage accumulation processes. Clear difference on damage accumulation process between standard laminates and thin-ply laminates was identified; fiber fractures were susceptible to formation in thin-ply laminates. Finally, the reason of the difference on damage process was investigated using finite element analyses, and it was clarified that the accumulated delamination position has a significant effect on the fiber fractures during the indentation. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.compstruct.2010.06.016

Web of Science

Scopus

Coupled thermal-electrical analysis for carbon fiber/epoxy composites exposed to simulated lightning current Reviewed

Toshio Ogasawara, Yoshiyasu Hirano, Akinori Yoshimura

COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING Vol. 41 ( 8 ) page： 973 - 981 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

A coupled thermal-electrical analysis of carbon fiber reinforced polymer composites (CFRP) exposed to simulated lightning current was conducted in order to elucidate the damage behavior caused by a lightning strike with the numerical results being compared to experimental results. Based on the experimental results and a preliminary analysis, the specific mechanism of electrical conduction through the thickness direction of CFRP following thermal decomposition was revealed to be a key parameter for accurate numerical simulation. In particular, assuming the electrical conductivity in the thickness direction to be linear with respect to temperature in the range from the epoxy decomposition temperature to carbon sublimation temperature produced reasonable numerical results. The delamination area and damage depth were estimated from numerical results and thermal decomposition behavior of CFRP with the estimated damage area agreeing qualitatively with the experimental results. Numerical results suggest that Joule heat generation significantly influences lightning strike damage. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.compositesa.2010.04.001

Web of Science

Scopus

Experimental characterization of high-speed impact damage behavior in a three-dimensionally woven SiC/SiC composite Reviewed

K. Ogi, T. Okabe, M. Takahashi, S. Yashiro, A. Yoshimura, T. Ogasawara

Composites Part A: Applied Science and Manufacturing Vol. 41 ( 4 ) page： 489-498 2010.4

A Numerical Simulation of Time-Dependent Interface Failure Under Shear and Compressive Loads in Single-Fiber Composites Reviewed

Jun Koyanagi, Akinori Yoshimura, Hiroyuki Kawada, Yuichiro Aoki

APPLIED COMPOSITE MATERIALS Vol. 17 ( 1 ) page： 31 - 41 2010.2

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

We performed a numerical simulation of a time-dependent interfacial failure accompanied by a fiber failure, and examined their evolution under shear and compressive loads in single-fiber composites. The compressive load on the interface consists of Poisson's contraction for matrix resin subjected to longitudinal tensile load. As time progresses, compressive stress at the interface in the fiber radial direction relaxes under the constant longitudinal tensile strain condition for the specimen, directly causing the relaxation of the interface frictional stress. This relaxation facilitates the failure of the interface. In this analysis, a specific criterion for interface failure is applied; apparent interfacial shear strength is enhanced by compressive stress, which is referred as quasi-parabolic criterion in the present study. The results of the stress recovery profile around the fiber failure and the interfacial debonding length as a function of time simulated by the finite element analysis employing the criterion are very similar to experimental results obtained using micro-Raman spectroscopy.

DOI： 10.1007/s10443-009-9118-2

Web of Science

Scopus

Evaluation of Gas Permeability of CFRP Laminates under Cyclic Loadings Reviewed

YOKOZEKI Tomohiro, KURODA Akiko, YOSHIMURA Akinori, OGASAWARA Toshio, AOKI Takahira

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN Vol. 8 ( 27 ) page： Pc_5-Pc_9 2010

Coupled Thermal-Electrical Analysis for Carbon Fiber Composites Exposed to Simulated Lightning Current Reviewed

OGASAWARA Toshio, HIRANO Yoshiyasu, YOSHIMURA Akinori

JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES Vol. 57 ( 667 ) page： 336-343 2009.8

Language：Japanese Publishing type：Research paper (scientific journal)

This paper presents coupled thermal-electrical analysis of transient temperature distribution in carbon fibre composites (CFRP) exposed to simulated lightning current to understand the damage behaviour due to lightening strike. Thermal and electrical properties of CFRP were evaluated for each direction of the unidirectional composites. The thermal decomposition behaviour was also estimated from thermo-gravimetric analysis results. Based on the experimental results and preliminary analysis results, the electrical and thermal boundary conditions were discussed in detail. The numerical results are directly compared with the experimental results, and the damage mechanisms of CFRP exposed to impulse current were considered. As a result, it was inferred that the delamination of CFRP was mainly caused by the decomposition of matrix resin, and the fibres were broken by the sublimation due to high Joule heat generation.

DOI： 10.2322/jjsass.57.336

Damage Growth Analysis in Particle Reinforced Composites by Using Cohesive Elements Reviewed

YOSHIMURA Akinori, OKABE Tomonaga

Journal of the Japan Society for Composite Materials Vol. 35 ( 3 ) page： 112-120 2009.5

Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)

The present paper proposes a simple numerical analytical method for crack extension simulation in the particle reinforced composite, and reveals the effect of crack extension on the macroscopic material properties of the particle reinforced composite. This numerical method is based on the homogenization method and Dugdale-type cohesive elements. In the present paper, we first present the formulation of the numerical model. We then verify the validity of the numerical model by comparing the simulated crack extension with the linear fracture mechanics. Finally we perform the crack extension simulation for the composite reinforced by spherical particle. We consider the inclusion crack and interfacial crack between inclusion and matrix. The analytical results reveal that the inclusion crack extends always unstably regardless of the size of initial crack, and the evolution of inclusion crack sharply decreases the apparent Young's modulus in the perpendicular direction to the crack surface and shear modulus in the out-of-plane direction of crack surface. The results also demonstrated that the interfacial crack always extends stably regardless of the size of initial crack, and the evolution of interfacial crack gradually degrades the stiffness in all direction.

DOI： 10.6089/jscm.35.112

Improvement of out-of-plane impact damage resistance of CFRP due to through-the-thickness stitching Reviewed

A. Yoshimura, T. Nakao, S. Yashiro, N. Takeda

Advanced Composite Materials Vol. 18 ( 2 ) page： 121-134 2009.5

Permeation-after-impact Properties of CFRP Laminates for Use on Propellant Tank Reviewed

YOKOZEKI Tomohiro, KURODA Akiko, YOSHIMURA Akinori, OGASAWARA Toshio, AOKI Takahira

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN Vol. 7 ( 26 ) page： Pc_19-Pc_23 2009

板厚方向の縫合によるCFRP積層板の面外衝撃損傷抑制効果 Reviewed

吉村彰記, 仲尾知晃, 武田展雄

日本複合材料学会誌 Vol. 34 ( 5 ) page： 182-188 2008.9

円孔を有する縫合CFRP 積層板の損傷進展 Reviewed

吉村彰記, 矢代茂樹, 武田展雄

日本複合材料学会誌 Vol. 34 ( 1 ) page： 14-20 2008.1

Improvement on out-of-plane impact resistance of CFRP laminates due to through-the-thickness stitching Reviewed

Composites Part A: Applied Science and Manufacturing Vol. 39 page： 1370-1379 2008

薄層化によるCFRP積層板の耐漏洩特性の向上 Reviewed

横関智弘, 高木智宏, 吉村彰記, 小笠原俊夫, 荻原慎二

日本航空宇宙学会論文集 Vol. 56 ( 657 ) page： 492-497 2008

Characterization of tensile damage progress in stitched CFRP laminates Reviewed

A. Yoshimura, S. Yashiro, T. Okabe, N. Takeda

Advanced Composite Materials Vol. 16 ( 3 ) page： 223-244 2007

縫合CFRP 積層材の引張負荷下における損傷進展挙動 Reviewed

吉村彰記, 矢代茂樹, 岡部朋永, 武田展雄

日本複合材料学会誌 Vol. 32 ( 5 ) page： 198-207 2007

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