Faculty Profiles - YOSHIMURA Akinori

Papers - YOSHIMURA Akinori

Division display 41 - 60 of about 78 ／ All the affair displays >>

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

　 PREV - NEXT 　

<YOSHIMURA Akinori>

Papers - YOSHIMURA Akinori