論文 - 森田 千尋
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Mechanical behavior of structural steel clad by wire arc thermal spraying 査読あり
Horisawa E., Matsumura M., Matsumoto R., Tanimoto T., Sugiura K., Morita C.
Journal of Constructional Steel Research 234 2025年11月
掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Constructional Steel Research
Thermal spraying is a surface modification technique in which molten particles are deposited to form protective or functional coatings. This study investigated the mechanical behavior of structural steel components strengthened by wire arc thermal spray cladding. The thermal spraying process was performed using martensitic stainless steel wire to achieve a target cladding thickness of approximately 5 mm. Tensile, compression, and bending tests were conducted to evaluate the mechanical performance of the cladding under various loading conditions. The cladding exhibited a Young's modulus of 70 GPa, approximately one-third that of bulk steel. The tensile strength of the cladding was estimated at 231 MPa, with brittle fracture occurring at a strain of 0.3 %. Despite its limited tensile ductility, the cladding contributed to an increase in axial stiffness in the elastic range. In contrast, under compression, the cladding exhibited ductile nonlinear behavior and failed by vertical cracking. The 0.2 % proof stress of the cladding in compression was 1.3 times that of the substrate, indicating adequate load-bearing capacity under compressive stress. In bending tests, the maximum load of clad steel plates was five times that of unclad steel plates, although cracking and debonding of the cladding were observed. These findings suggest that cladding applied by thermal spraying has mechanical characteristics suitable for structural applications, particularly under compressive stress.
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CNN AND GAN BASED WEATHERING STEEL APPEARANCE EVALUATION IMPROVED BY IMAGE SIZE AND LOSS FUNCTION 査読あり
Nagatani K., Shigei N., Morita C., Ishizuka Y., Miyajima H.
International Journal of Innovative Computing, Information and Control 21 ( 2 ) 433 - 445 2025年4月
掲載種別：研究論文（学術雑誌） 出版者・発行元：International Journal of Innovative Computing, Information and Control
Weathering steel is a steel material that can maintain its performance outdoors for a long period of time by forming protective rust. Periodic inspection of the rust condition is necessary to maintain this steel in good condition, and CNN-based methods for evaluating the appearance of rust have been studied. One of the problems in improving the classification accuracy of the CNN is how to prepare the rust images for training. The objectives of this paper are 1) to consider rust patch image size and 2) to improve the diversity of the generated images in rust image generation using GAN. From 1), we show that the accuracy can be improved by using large cropping images and shrinking the image when training the model. From 2), we propose SSIM-target loss, which is an improvement of the conventional SSIM loss, and show that it improves the CNN Score. Using methods 1) and 2), we achieved an F1 score of 90.3% for the three-class classification of the rust images, compared to the baseline method’s F1 score of 86.8%.
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耐候性鋼橋梁のさび外観評点と健全性評価に関する考察 査読あり
中島和俊, 加納勇, 安波博道, 今井篤実, 高木優任, 森田千尋
構造工学論文集 71A 351 - 361 2025年3月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：公益社団法人 土木学会
In this study, the appearance rating method, which is now widely used to diagnose the integrity of weathering steel bridges, was reorganized based on photographs and the amount of corrosion in previous studies to clarify the classification of each category. This clearly separated the categories that should be repaired (Rating Number 1) from the others. In addition, it was also possible to determine that the rusting changes over time would not naturally shift to the rating number 1, although there is a possibility that the rusting changes from rating number 5 to rating number 2 would shift sequentially. This has enabled us to propose a more rational method for soundness diagnosis during periodic inspections.
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Numerical study on the melting behavior of annular fuel under accident conditions 査読あり 国際共著
Wang B., Huang M., Meng X., Ouyang X., Huang Y., Matsuda H., Morita C.
Progress in Nuclear Energy 179 2025年1月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Progress in Nuclear Energy
The use of annular fuel in nuclear power plants has been developed to improve their efficiency, safety, and economic viability. Therefore, studying the thermal hydraulic issues of annular fuel is crucial. The melting of annular fuel under accident conditions is equally important. This study uses a novel numerical technique called the Half Boundary Method (HBM) to tackle this issue. With new variables introduced, this method avoids the need for additional continuity equations at the boundary when solving multi-layer composite problems. First, the HBM is used to model a multi-layer composite ring and solve its transient thermal problems, which are then verified. Next, the temperature distribution of annular fuel under operational conditions is calculated, and the results are compared to validate HBM's accuracy. Based on these findings, simulations are conducted to model the melting phase transitions of annular fuel during Loss of Coolant Accidents (LOCAs) and Reactivity Insertion Accidents (RIAs).
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Improvement of GAN-based Training Image Generation for CNN-based rust Evaluation of Weathering Steel 査読あり
Nagatani K., Shigei N., Morita C., Ishizuka Y., Miyajima H.
ACM International Conference Proceeding Series 40 - 47 2024年12月
掲載種別：研究論文（学術雑誌） 出版者・発行元：ACM International Conference Proceeding Series
Weathering steel is a steel material that produces a protective rust layer on the surface of the steel that suppresses the propagation of corrosion. Periodic inspection of the rust condition is necessary to maintain this steel in good condition, and CNN-based methods for evaluating the appearance of rust have been studied. One of the problems in improving the classification accuracy of the CNN is how to prepare the rust images for training. Since it is difficult to collect rust images in the real world, it has been studied to train CNN with rust images generated by GANs. Conventional GANs have the problem that when a large number of images are generated, the generated images are biased toward similar ones. The scope of this paper is to improve the accuracy of CNN using GAN-generated images in classification tasks of rust conditions of weathering steel. The specific objectives of this study are to improve the diversity of images generated by GANs and thereby improve the accuracy of CNNs. To improve image diversity in GAN-based image generation, we propose to use Wasserstein GAN with Gradient Penalty (WGAN-GP), in addition to Conditional GAN (CGAN), and to introduce SSIM (Structural Similarity) and LBP (Local Binary Pattern) as loss functions, in addition to L1 and L2 losses. Then, the images generated by the proposed five types of GANs are applied to the training of CNNs. Comparison between the proposed GANs and the conventional CGAN shows that 1) the proposed GANs can reduce the SSIM similarity of the generated images by up to 1/4, and 2) in the classification of three classes of rust images, the use of the generated images of the proposed GANs can improve the F1 score by up to about 4%pt. Overall analysis shows that WGAN-GP-based is better than CGAN-based and that the newly introduced SSIM, LBP, L1 and L2 losses improve both similarity and classification accuracy.
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A boundary-type algorithm based on the discrete ordinates for neutron transport equation 査読あり 国際共著
Cheng Y.T., Huang M., Ouyang X.P., Matsuda H., Morita C.
Engineering Analysis with Boundary Elements 169 2024年12月
掲載種別：研究論文（学術雑誌） 出版者・発行元：Engineering Analysis with Boundary Elements
The spatial distribution of neutron flux in the core of a nuclear reactor plays a crucial role in ensuring nuclear safety. It can be determined by solving the neutron transport equation, where computational resource consumption is gradually receiving more attention, especially in problems with multiple reflective boundary conditions. It is common practice to assume initial boundary values in one angular direction to obtain a global solution, and then use reflective boundary conditions to solve for the other directions, iterating until convergence. However, this approach has the drawback of requiring the global solution, and each iteration necessitates storing the neutron flux values, consuming time and storage space. In order to address this issue, this paper proposes a precise and efficient boundary-type method, the Half Boundary Method (HBM). This method establishes relationships between adjacent node values through integration and mathematical deduction, ultimately obtaining the relationship among any node and the boundary values in any direction. As a result, iteration is only required for boundary values, reducing the iteration amount and thus saving time and storage space. Using the discrete ordinate (SN) method for angular discretization and HBM for spatial discretization, this paper solved the steady-state neutron transport equation for two-dimensional systems modeled with Cartesian geometry. The method is validated using several benchmark problems, including the 2D ISSA benchmark, the 2D mono-group k-eigenvalue problem and BWR rod bundle test problem. All of these problems demonstrate good results and effectively reduced computational time.
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Nakano A., Toyota Y., Morita C., Yasui K., Oshikawa W., Yonezawa N.
International Journal of Steel Structures 2024年9月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Journal of Steel Structures
This paper presents the results of a study comparing the initial corrosion characteristics of thermal spray coatings on Zn, Zn-Al, and Al–Mg thermal spray coatings after one year atmospheric exposure tests at two atmospheric environment sites. The thermal spray coatings were obtained by electroric arc spraying of various metals onto a carbon steel substrate. Atmospheric exposure tests were also conducted for outdoor accelerated exposure tests in which test specimens were applied with artificial seawater. The corrosion properties of these spray coatings were evaluated by surface analysis, film thickness measurements, cross-sectional analysis and anodic/cathodic polarization measurement. After one year of atmospheric exposure testing, white, granular corrosion products were observed on the surface of the Zn and Zn-Al thermal spray coatings, while no significant changes were observed in the Al–Mg thermal spray coating. Similar results were obtained for the surfaces of test specimens in atmospheric exposure tests with artificial seawater. The thickness of the thermal spray coating increased for the Zn thermal spray coating, while no significant change was observed for the other thermal spray coatings. Thus, differences in corrosion behavior were observed due to the composition of the thermal spray coatings. The initial corrosion behavior of the thermal spray coatings was also investigated based on the results of coating morphology and cross-sectional elemental distribution of the coatings.
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特集「建造物とインフラ管理における計測技術」の編集にあたって 招待あり
森田 千尋
実験力学 24 ( 2 ) 42 - 42 2024年6月
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Yasui K., Sakaida Y., Yamamura K., Minamimagari M., Horisawa E., Morita C., Kinoshita H.
Sustainability (Switzerland) 16 ( 12 ) 2024年6月
掲載種別：研究論文（学術雑誌） 出版者・発行元：Sustainability (Switzerland)
Bora is a granular volcanic pumice with a certain degree of hardness. In this study, we investigated the possibility of using fired Bora as a substitute for fine sand in mortar. The objective was to develop a lightweight pavement block with extremely high permeability using fired Bora. Initially, the changes in hardness and density of Bora particles fired at different temperatures were examined. The bending strength of mortar containing fired Bora as a fine aggregate was also evaluated. Subsequently, we fabricated a permeable pavement block with a hybrid structure, comprising a mortar containing the fired Bora and a porous material with large-sized Bora particles bonded using cement paste. We examined its bending strength and permeability and performed a quantitative analysis of the bending stress distribution on the block using the finite element method. The hardness of Bora significantly increased when fired at temperatures exceeding 900 °C; hence, Bora fired at 1100 °C can be used as an effective substitute for crushed sand in mortar. Furthermore, the results confirmed that the use of fired Bora enabled the production of lightweight pavement blocks with extremely high permeability that satisfied the bending strength criterion.
DOI： 10.3390/su16124888
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Statistical damage constitutive model for rocks considering temperature effects and its validation 査読あり 国際共著
Wei C., Zhao C., Zhao C., Matsuda H., Morita C.
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) 55 ( 3 ) 1056 - 1067 2024年3月
掲載種別：研究論文（学術雑誌） 出版者・発行元：Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology)
In order to predict and evaluate the stability of deep high-temperature rock masses, theoretical derivation methods were used to study the constitutive relationship of rocks under (after) temperature action. Firstly, based on existing rock statistical damage constitutive models, the influence of temperature on rock damage variables was considered, and parameters such as damage variable correction coefficient, damage initiation stress, and initiation strain were introduced. Secondly, it is assumed that the strength of the microelements follows a power function distribution and conforms to the Hoek- Brown (H-B) strength criterion. In response to the drawback that statistical damage constitutive models cannot reflect the strong prepeak microcrack compaction effect, corresponding model correction coefficients were introduced. Thirdly, a rock statistical damage constitutive model considering temperature effect was established, and the expression of model parameters was determined. Finally, the accuracy of the model was verified by comparing the data obtained from uniaxial and conventional triaxial compression tests on granite under different temperature conditions with the calculation results of the model in the literature. The results show that the calculation results of the proposed model are consistent with the experimental results in literature in terms of numerical values, distribution patterns and trends. For each stage of the whole process σ-ε curve, the calculation result of the model in this paper is better than that of the constitutive model in the literature, and fits with the test curve better, which can better reflect the damage constitutive characteristics of rock under (after) high temperature. The parameters of the model are conventional and suitable for rocks under various temperature-pressure combination conditions.
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宮崎県内の耐候性鋼橋梁におけるさび状態の経年変化
清瀬啓文，森田千尋，別府渓太，安井賢太郎
九州橋梁・構造工学研究会シンポジウム論文集 11 54 - 58 2023年12月
担当区分：責任著者 記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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Atmospheric corrosion properties of thermally sprayed Zn, Zn–Al, and Al-Mg coatings exposed under different atmospheric environment 査読あり
Y. Toyota, A. Nakano, C. Morita, K. Yasui, W. Oshikawa and N. Yonezawa
Proceedings of ISSS 2023 12 303 - 306 2023年11月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
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A Study on Bridge Inspection Method Using UAV and SfM 査読あり
J. Sakoda, C. Morita, K. Yasui and A. Demizu
Proceedings of ISSS 2023 12 299 - 302 2023年11月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
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球磨川における被災橋梁の復旧状況調査とモバイルブリッジの実用性の検討
豊田祐樹，上別府尚弘，森田千尋
宮崎大学工学部紀要 52 31 - 39 2023年11月
担当区分：責任著者 記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
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Half boundary method for two-dimensional steady-state nonlinear convection-diffusion equations 査読あり 国際共著
Meng X., Huang M., Wang B., Li Y., Cheng Y., MORITA C.
Engineering Analysis with Boundary Elements 150 187 - 198 2023年5月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Engineering Analysis with Boundary Elements
In this research, half-boundary method (HBM) is developed for nonlinear convection-diffusion equations (CDEs) which play an important role in applied mathematics and physics. The HBM is based on the variable relationship between the nodes inside the domain and the nodes on half of the boundaries, making it ideal for reducing the maximum order of matrix and calculation memory storage. Besides, the HBM can solve discontinuous problems directly without adding continuity conditions due to the use of the mixed variables. The effectiveness and accuracy of the proposed algorithm are investigated mainly for the two-dimensional(2D) steady-state Burgers’ equation, the material nonlinear 2D CDEs and the system of 2D Burgers’ equations. The results show the excellent performance of the HBM in simulating flow and heat transfer, especially for convection domination.
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防災・減災のための緊急仮設橋の設計および設計基準の課題 査読あり
渡邊学歩，佐々木貴信，森田千尋，小林博之，勝呂翔平，松田伊佐雄，木下幸治
構造工学論文集 69A 1258 - 1268 2023年3月
担当区分：責任著者 記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：公益社団法人 土木学会
In this study, the operational records of temporary bridges, definitions of temporary bridges, and applicable technical standards were reviewed, and these issues were clarified. The results of trial designs of emergency bridges show that the elimination of regulation of the deflection enables the rational design and construction of temporary bridges using readily available materials. In addition, the necessity of technological development for the design of structural details, clarification of performance requirements, and standardization of design is proposed to reduce the construction cost of temporary bridges and to speed up their construction.
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中小規模橋梁の復元設計におけるSfM活用の基礎的検討
本多雅匠，塩竃柚貴，森田千尋，安井賢太郎，中丸ゆかり
宮崎大学工学部紀要 51 7 - 14 2022年11月
担当区分：責任著者 記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
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Baggingと複数のパッチ画像を用いたCNN識別器による耐候性鋼材のさびの外観評価手法 査読あり
有村和也，重井徳貴，森田千尋，石塚洋一，宮島廣美
知能と情報 34 ( 2 ) 533 - 538 2022年5月
記述言語：日本語 掲載種別：研究論文（学術雑誌）
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CFD investigation for a 7-pin wrapped-wire fuel assembly with different wires 査読あり 国際共著
Lin J., Huang M., Zhang S., Wang B., Huang J., Matsuda H., Morita C.
Annals of Nuclear Energy 164 2021年12月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Annals of Nuclear Energy
The fuel rods of the fast reactor are radially and axially fixed and supported by wrapped-wire. The wrapped-wire not only prevents the fuel rod from vibrating but also stirs the coolant, thereby enhancing heat transfer. This paper uses the SST k–ω turbulence model and commercial CFD software to investigate the effect of the number of the wrapped-wires on flow field. The results show that under normal operating conditions, the increase of the number of wrapped wires will increase the pressure difference, but it is conducive to the mixing of the flow field due to the regular eddy current phenomena caused by uneven pressure distribution, which is one of the reasons that affect the convective heat transfer of fuel assemblies.
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Zhang R., Zhao C., Yang C., Xing J., Morita C.
Computers and Geotechnics 140 2021年12月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Computers and Geotechnics
Understanding the mechanisms of crack initiation and development is important for utilizing the hydraulic fracturing in practical engineering applications. In this study, hydraulic fracturing experiments were conducted on granite specimens containing a single pre-existing flaw, and the failure processes were analyzed using the digital image correlation method. A flat-jointed bonded particle model was built with a modified fluid flow algorithm to better understand the fracture behavior under the experimental conditions. Combining the DIC strain fields and the simulated displacement fields, we found that shear behavior with a small value also emerges ahead of the tips of the microcracks and was covered by the subsequent tensile behavior, as a result, shear strain could not be observed in the experiments. A comparison between the strain localization and the microcracks revealed that the fracturing process observed in the experiments had two stages: the isolated strain localization formed during Stage I, mainly resulting from the increase in microcracks, and the continuous high tensile strain path formed during Stage II. Additionally, the effect of the different flaw inclination angles was discussed from two perspectives: the different types of macrocracks and the change in the fracturing liquid pressure.
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Temperature deformation characteristics of acrylic windows used for tide embankments 査読あり
Yasui K., Shiokawa A., Watanabe M., Kinoshita H., Morita C.
AIMS Materials Science 8 ( 6 ) 932 - 951 2021年12月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：AIMS Materials Science
Tide-embankment walls protecting coastal roads frequently contain numerous windows so that pedestrians and drivers can view the scenery without experiencing reduced sunlight. Tide-embankment windows must withstand extreme climatic conditions. However, the effects of temperature extremes on acrylic boards have rarely been studied. This paper proposes a simple method for constructing a high-temperature environment and a method for measuring strain on an acrylic plate. The deformation and strain of a 40-mm-thick acrylic tide-embankment window were determined experimentally and numerically in this study in a high-temperature environment, obtaining similar results; additionally, the numerical method was subsequently used to simulate a low-temperature environment. Because thermal conductivity was low, the internal temperature of the thick acrylic board did not immediately change with the temperature of the surface, and thermal expansion and contraction of the board were restrained. Temperature-induced deformation effects were low across the entire range of temperatures and heating rates recorded in coastal Japan.
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Al系溶射皮膜の長期大気暴露試験における耐候性評価 査読あり
中野敦，白井敬大，森田千尋，押川渡，米沢昇
鋼構造年次論文報告集 29 526 - 537 2021年11月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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Pan H., Zhao C., Xing J., Zhang R., Morita C.
IOP Conference Series: Earth and Environmental Science 861 ( 7 ) 2021年10月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：IOP Conference Series: Earth and Environmental Science
The discrete element method is widely used in rock mechanics, but its computational efficiency limits its development. To improve the accuracy of a discrete element model, the particle size of the entire model needs to be decreased according to the current theory. However, only the range of interest (ROI) is usually concentrated, and the background (BG) refinement is a waste of computing power. The paper proposes a gradient particle size specimen modeling scheme. The resolution of ROI is increased while the resolution of BG is retained. The probability of particle generation is derived from the statistical point of view that the porosity should be consistent. The computational performance is analyzed from the perspective of time complexity. With the edge particle size being 2.0 times the central particle size, only about 26% of the computing time is required. A series of unconfined compression experiments are subsequently carried out to verify the modeling scheme. The characteristics of the gradient particle specimen modeling scheme and the uniform particle size specimen modeling scheme are highly consistent, including the load-deform curves, crack progress curves, crack initiation patterns, and failure patterns. Finally, the deficiencies of the modeling scheme are discussed, including the unconfined compressive strength (UCS) reduction, which is probably due to the reduction of the coordination number. Further research will be conducted.
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Qian Y., Zhao C., Xing J., Zhou Y., Morita C.
IOP Conference Series: Earth and Environmental Science 861 ( 7 ) 2021年10月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：IOP Conference Series: Earth and Environmental Science
Damage and fracture of rocks is a comprehensive result of strain energy dissipation and release. In order to study the energy evolution mechanism of hard brittle rock masses during failure process, uniaxial compression tests on the granite specimens with a single pre-existing flaw are carried out with digital image correlation method (DIC). The results indicate that: (1) The stress fluctuation before structural failure corresponds to the sudden increase of the dissipated energy, the essence is that rock masses occur obviously damage and cracking. (2) For medium flaw dip angles, the stress fluctuation occurs repeatedly in stages, whose strain energy is dissipated gradually; for large or small dip angles, the stress fluctuation is almost not appeared, and the energy dissipation is insignificant. (3) With the increase of flaw dip angles, the dissipated energy ratio at the peak stress first increases and then decreases showing an inverted U-shaped, resulting in a similar law of rock damage but a contrary law of strength; the corresponding elastic energy ratio is U-shaped of decreasing first and then increasing, causing the structural failure changes from dynamic to static and then to dynamic again. The results can provide theoretical references for the formation mechanism and prevention method of dynamic disasters of rock underground engineering.
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複数の CNN 識別器を用いた複数のパッチ画像からの耐候性鋼材のさびの外観評価
有村 和也, 重井 徳貴, 森田 千尋, 石塚 洋一, 宮島 廣美
日本知能情報ファジィ学会 ファジィ システム シンポジウム 講演論文集 37 ( 0 ) 694 - 698 2021年9月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：日本知能情報ファジィ学会
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UAVとSfM技術を利用したコンクリート構造物のひび割れ幅計測の道路橋への適用 査読あり
本多雅匠, 森田千尋, 安井賢太郎, 出水享, 中野敦
実験力学 21 ( 3 ) 232 - 239 2021年9月
担当区分：責任著者 記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：日本実験力学会
Aging road bridges have become a problem in Japan, and regular inspections are carried out once every five years by proximity visual inspection. However, the shortage of inspection technicians and budget is a problem, and there is a need for inspection technology that is efficient and can perform diagnosis equivalent to proximity visual inspection. In this study, we focused on the image processing technology of the 3D data generation software SfM, generated a 3D model from the crack image of the concrete member taken by UAV, and compared the actual crack width with the crack width obtained from the 3D model. As a result of the verification, it was suggested that by using UAV and SfM, the crack width of 0.2 mm or more can be judged with relatively high accuracy by photographing the area around the actual crack from a short distance.
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Al-5mass%Mg合金溶射皮膜の耐食性に関する研究
白井敬大，中野敦，森田千尋，押川渡，米沢昇
九州橋梁・構造工学研究会シンポジウム論文集 8 35 - 40 2020年12月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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複数のパッチ画像を用いたCNNによる耐候性鋼材のさびの外観評価
有村和也、重井徳貴、森田千尋、石塚洋一、宮島廣美
日本知能情報ファジィ学会九州支部学術講演会予稿集 22 21 - 25 2020年11月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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腐食促進環境下におけるAl系擬合金及び合金溶射皮膜の防食特性 査読あり
中野敦，白井敬大，森田千尋，押川渡，米沢昇
鋼構造年次論文報告集 28 19 - 25 2020年11月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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Atmospheric Corrosion Behavior of Arc Thermal Spray Zn-Al Coatings Using Accelerated Atmospheric Field Test for Ten-Year
A. Nakano, W. Oshikawa, N. Yonezawa, C. Morita and Y. Shirai
ECSarXiv Preptints 2020年10月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
DOI： 10.1149/osf.io/59ykt
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Weatherability of Arc Thermal Spray Al-Mg Coating in a Simulated Marine Environment
A. Nakano, W. Oshikawa, N. Yonezawa, C. Morita and Y. Shirai
ECSarXiv Preptints 2020年10月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
DOI： 10.1149/osf.io/zq9x2
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Mechanical Characteristics of the Butterfly Bridge Using the Finite Element Method
Asri saputra HENDRA, Chihiro MORITA, Shunsuke FUKAMI, Motohiro OSHIKATA
Memorirs of Faculty of Engineering University of Miyazaki 49 1 - 6 2020年9月
記述言語：英語 掲載種別：研究論文（大学，研究機関等紀要）
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人工海水を用いた腐食環境下におけるZn-30mass%Al溶射皮膜の大気暴露特性 査読あり
中野敦, 押川渡, 米沢昇, 森田千尋, 白井敬大
鋼構造論文集 27 ( 106 ) 106_51 - 106_60 2020年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：社団法人 日本鋼構造協会
A nine-year atmospheric exposure test was performed on Zn-30mass%Al thermal spray coating under the corrosion environment using the artificial sea water. A similar corrosion test carried out to compare the properties with Hot-dip-Zinc coating. Atmospheric corrosion properties of thermal spray coating were evaluated by surface observation, X-ray diffraction, film thickness measurement and element analyses using EPMA. From these analysis results, the thickness of thermal spray coating was not impacted greatly under corrosion environment using the artificial sea water. In addition, corrosion resistance of Zn-30mass%Al thermal spray coating is much higher than that of Hot-dip-Zinc coating.
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Zhao Y., Huang M., Ouyang X., Tang J., Morita C.
Engineering Analysis with Boundary Elements 113 26 - 39 2020年4月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Engineering Analysis with Boundary Elements
© 2019 Convection-diffusion equation is widely used in many fields of science, technology and engineering. The calculation is usually difficult and time-consuming. In this paper, a highly efficient meshless boundary type method called the half boundary method (HBM) is applied to solve convection diffusion equation. The main idea of HBM is to reduce the order of the convection–diffusion equations by introducing new variables and construct the relations of the variables between the nodes inside the area and the nodes on half of the boundaries by using integration, inverse matrix and reasonable transformation. Using the relations, the temperature and heat flux at any point can be calculated simultaneously after obtaining the variables on half of the boundaries according to the boundary conditions. Given that unknown variables exist only on half of the boundaries, the internal storage in the HBM is less than that required in the finite volume method when the division number is large. And it doesn't need shape functions in the finite element method or a fundamental solution in the boundary element method. HBM can obtain very precise results when solving the convection dominated problems. The validity and accuracy of the proposed method are authenticated by the numerical examples.
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A new procedure for solving neutron transfer problems 査読あり
Tang J., Huang M., Zhao Y., Ouyang X., Morita C.
Annals of Nuclear Energy 138 2020年4月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Annals of Nuclear Energy
© 2019 Elsevier Ltd In this paper, we propose an accurate and efficient procedure named half boundary method (HBM) to solve one-dimensional neutron transfer problems. In the process of solving the Boltzmann transfer equation, the relationships between every two neighboring nodes are solved first. Then, starting from a vacuum boundary, the neighboring relationships are iteratively applied to solve the neutron distribution. In two reflective boundaries problems, the reflective boundaries are applied to solve the neutron flux at the boundaries first, then the neutron distribution is solved similar to the vacuum boundary problems. Different from the traditional method, no matter how many segments are dispersed, at most two-order matrixes are involved in HBM calculations. So, HBM shows great potential in saving computational memory, particularly for problems with huge girds. In this paper, we introduce the fundamental theory and investigate the applicability, accuracy, and efficiency of HBM by solving five examples with different situations and boundaries.
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SfMを用いた構造物の３次元モデル化について
小川裕棋、森田千尋、松川尚史、塩竃柚貴、白井敬大
「歴史的構造物の非破壊検査」ミニシンポジウム論文集 3 41 - 46 2020年3月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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Zhao C., Niu J., Zhang Q., Yu S., Morita C.
Journal of Materials in Civil Engineering 31 ( 12 ) 2019年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Materials in Civil Engineering
© 2019 American Society of Civil Engineers. The expanded distinct element method based on a strain strength criterion was applied herein with the aim of analyzing and comparing the cracking behaviors of rock-like specimens with single flaws under uniaxial and biaxial compressions. The cracking characteristics in uniaxial and biaxial compressions were compared and the effects of confining pressure on the tensile/shear behaviors were analyzed. The confining pressure obviously changed the boundary condition and the cracking behaviors in biaxial compression. The initiation stress, the peak strength, and the number of shear cracks in biaxial compression were obviously larger than in uniaxial compression. The confining pressure affected the initiation and propagation of the secondary cracks, the failure mechanisms, and the distribution of horizontal displacement fields in a large extent. The initiation and propagation of the tensile cracks were inhibited by the confining pressure. An increase in confining pressure had no obvious effects on the initiation time and the propagation rates of the shear cracks but mainly affected the numbers of shear cracks.
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人工海水腐食環境下におけるZn-Al溶射皮膜の腐食性評価 査読あり
森田千尋，中野敦，白井敬大，押川渡，米沢昇
鋼構造年次論文報告集 27 374 - 383 2019年11月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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A HBM approach for temperature and heat flux convection–diffusion equations and nonlinear problems 査読あり
Zhao Y., Huang M., Tang J., Ouyang X., Morita C.
Nuclear Engineering and Design 342 115 - 127 2019年2月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Nuclear Engineering and Design
© 2018 Elsevier B.V. Solving convection diffusion equation is widely required in many fields of science, technology and engineering. The calculation is usually difficult and time-consuming. In this paper, a highly efficient method, the half boundary method (HBM), is proposed to solve the convection diffusion equation. The main idea of HBM is to reduce the order of the convection–diffusion equations by introducing a new variable and constructing the relations of the variables between the nodes inside the area and the nodes on half of the boundaries. Using the relations, the temperature and heat flux at any point can be calculated simultaneously, after obtaining the variables on the half of the boundaries. Because the unknown variables exist on only half of the boundaries, the computing matrix is reduced to only second order regardless of the number of nodes, the internal storage in the HBM is even less than that required in the finite volume method, making the HBM extremely fast and efficient. The validity and accuracy of the proposed method are investigated. Numerical studies for steady and unsteady, as well as nonlinear convection–diffusion equations, were carried out. The results show that HBM is more accurate than the finite volume method under identical grids conditions.
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中島和俊, 加納勇, 安波博道, 森田千尋
鋼構造論文集 25 ( 98 ) 35 - 43 2018年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：社団法人 日本鋼構造協会
The soundness evaluation of weathering steel bridges is generally based on external visual inspection and is not quantitative, it is known that it greatly influences the experience and subjectivity of the evaluator. In this study, patch type exposure tests were conducted on 7 bridges of weathering steel bridges managed by Nagasaki prefecture, and the soundness was evaluated based on corrosion prediction. Also, the corrosion behaviors of each part such as flange and web were analyzed and evaluated.
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シザーズ構造の力学特性に関する研究
池畑雄太，森田千尋，有尾一郎，濱優太，近広雄希
九州橋梁・構造工学研究会シンポジウム論文集 5 53 - 57 2017年12月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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インフラ再生技術者育成のための道守養成講座の構築と認定者の活用の取組み 査読あり
松田浩, 中村聖三, 森田千尋, 奥松俊博, 高橋和雄
土木学会論文集F4（建設マネジメント） 73 ( 4 ) I_21 - I_32 2017年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：公益社団法人 土木学会
インフラ再生を担う技術者育成の重要性に着目した長崎大学インフラ長寿命化センターは自治体，地域の建設業等からなるコンソーシアム"道守"養成ユニットを全国に先駆けて2008年度に設立した．社会人技術者を対象としたインフラの維持管理のキャリアを形成する学習ユニット積み上げ方式の道守養成講座のカリキュラムを開発し，人材育成を継続してきた．道守認定者の活動はこれまで主としてボランティアであったが，国土交通省による民間資格への登録を契機に維持管理に関する技術者としての活動が開始された．本論文は，道守養成講座の実施体制，養成講座のカリキュラム，達成評価基準，養成者数等の実績をこれまで蓄積された資料に基づいてまとめる．さらに，道守認定者の資格更新，認定後の自主的な活動，技術者としての活動等についてまとめる．
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アンケート調査に基づく道守認定者の活動・意向と道守養成ユニットへの反映 査読あり
高橋和雄, 松田浩, 中村聖三, 森田千尋
土木学会論文集F4（建設マネジメント） 73 ( 4 ) I_10 - I_20 2017年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：公益社団法人 土木学会
長崎大学は2008年度に全国に先駆けて自治体及び建設業界からなる産学官連携コンソーシアムにより，道路の維持管理を担う社会人技術者を育成する道守養成講座を開催してきた．道守養成講座の開始から7年が経過した2015年4月の時点で道守認定者は約200人に達し，公共工事等に活用できる程度の認定者数が確保された．道守認定者の活動，活用及び意向等はこれまで具体的に把握されていない．そこで，本アンケート調査により，道守認定者としての活動内容，技術者としての活動，道守に関する情報入手，組織化，道守認定者としての自己評価，今後の道守養成講座の実施等についての現状と課題を明らかにした．さらに，アンケート調査の結果に基づいた道守養成講座の見直し，道守認定者への情報提供方法，認定後の活動内容等についてまとめる．
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宮崎県における耐候性鋼橋梁の現状について 査読あり
森田千尋，野中拓海，大木翔太
鋼構造年次論文報告集 25 559 - 565 2017年11月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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塗膜除去不要な鋼部材疲労亀裂の熱的負荷による光学的全視野探傷法 査読あり
松田浩, 小金丸暁, 草野壱俊, 伊藤幸広, 森田千尋
土木学会論文集A2（応用力学） 72 ( 2 ) I_643 - I_652 2017年1月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：公益社団法人 土木学会
近年，道路橋の鋼製橋脚や鋼床版等の部材に疲労き裂の発生する事例が増加している．疲労き裂の発生部位によっては，進展すると脆性破壊を引き起こし，橋梁の安全性に重大な影響を及ばす恐れがある．したがって，それらを早い時期で発見し，適切な補修を行うことが重要である．本論文は熱源を用いてき裂を開閉させ，それを光学的全視野計測法の一つであるデジタル画像相関法（以下，DICMと表記）で計測することにより，塗膜除去を必要としないき裂発生を可視化させる新しい鋼部材のき裂欠陥検知法の開発を目的としたものである．
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Meso-experimental study of failure mechanism of rock based on uniaxial compression test 査読あり
Zhao C., Yu Z., Wang W., Matsuda H., Morita C.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering 35 ( 12 ) 2490 - 2498 2016年12月
記述言語：中国語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering
© 2016, Science Press. All right reserved. The evolution of microscopic fabric of rock has an important effect on its mechanical property and failure shape and it is therefore essential to study the microscopic fabric on rock. In this study, the scanning electron microscope(SEM) was used to scan the micro structure of the failure section of samples after compression shear test and Brazil split test. The morphological characteristics of the fracture surface of specimen were highlighted and the criteria of microscopic morphology matching macroscopic mechanical properties of crack surface were established. Meanwhile, the whole failure section of manufactured pre-crack was scanned with different angles of inclination. The criteria was applied to distinguish their microscopic morphology. As a result, the ratio of tensile-shear stresses on the fracture surface was obtained. The variation of the ratio in the cracking propagation process was studied. The results show that the ratio of tensile-shear stresses is closely related to the dip angle of the pre-existing crack. When the inclination angle is less than 45°, the tensile stress on the fracture surface is high, and the ratio decreases with the crack angle increasing. When the inclination angle is more than 45°, the results are opposite to the former. When the inclination angle is 45°, there are two macroscopic cracks owing to the combined effect of tensile and shear stresses. The proportion of wing cracks tensile stress changes from high to low during crack propagation process, and the results of secondary crack are converse to the former.
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Zhao C., Liu F., Tian J., Matsuda H., Morita C.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering 35 3626 - 3632 2016年10月
記述言語：中国語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering
© 2016, Science Press. All right reserved. Through laboratory test by employing the digital image correlation method(DICM), the laws of crack propagation and mechanism of plastic deformation of rock-like material with single crack pre-existing with various inclined angles when subjected to static loading are studied. The results show that when the inclined angle α = 15° and α = 30°, the position of the maximum strain is near the inner crack tip point, the new crack propagation begins at the initial crack wing, and the tension stress is the main reason of the new crack generation and propagation. With the increasing of α, when α = 60° and α = 75°, the strain concentration is detected at the crack tip. The main propagation mode of new cracks is secondary cracks, and the shear stress play a dominant role. There are both wing cracks and secondary cracks when α = 45°. The crack initiation stress increases as α increasing. The sample shows there are the minimum compression strength and the fastest crack propagation speed when α = 30°. The uniaxial compressive strength of the sample with secondary cracks is significantly higher than that sample with wing cracks.
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遠隔非接触振動計測装置を用いた橋梁の振動計測に関する研究—実橋梁計測のためのレーザ照射ターゲットの検討— 査読あり
森田千尋, 出水享, 松田浩, 岩吹啓史, 木本啓介
実験力学 16 ( 3 ) 243 - 249 2016年9月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：日本実験力学会
The technological development which efficiently checks the huge infrastructure structure is urgent need. From several years ago, we have studied using a laser Doppler velocimeter capable of remote non-contact measurement in vibration measurement. However, a seal for retro-reflection is employed as a laser illumination target by LDV measurement, but installation is sometimes difficult. Furthermore, it is difficult to multi-directional vibration measurement at a single target for normal measurement. Therefore, in order to solve the problems described above in the present study, we examined the new vibration measurement using heterologous laser irradiation targets.
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Zhao C., Bao C., Tian J., Matsuda H., Morita C.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering 34 ( 11 ) 2309 - 2318 2015年11月
記述言語：中国語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering
© 2015, Science Press. All right reserved. Cracks in rock will initiate, propagate and coalesce under loading, which remarkably influences the strength and damage property of rock. Based on a DIC system which was proved reliable, uniaxial compression experiments were carried out on the specimens with two precast flaws. The strain field and strain localization of the whole specimen were obtained. It was found that the strain localization and the progressive damage were very distinctive in the test. The strain localization zone appeared in the initial phase governed the range and trend of the whole process of the strain field development. There were four failure modes found in the test, that is the non-coalescence mode, the coalescence mode at inner tip of flaws, the coalescence mode at outer tip of fracture and the inner-outer tip coalescence mode. The bridge angle and the arrangements of flaws had the effect on the formation of strain localization zone in mesoscopic level and determined the cracking path and the failure mode in macroscopic level. The coalescence of strain localization zone in the bridge area resulted in a fluctuation of stress-strain curve before the peak and reduced the peak strength. The slower the coalescence of the strain localization zones, the higher the peak strength.
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Free vibration analysis of stepped rectangular plates resting on non-homogeneous elastic foundations 査読あり
Huang M., Sakiyama T., Matsuda H., Morita C.
Engineering Analysis with Boundary Elements 50 180 - 187 2015年1月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Engineering Analysis with Boundary Elements
© 2014 Elsevier Ltd. A Half Boundary Method (HBM) is proposed for analyzing the free vibration problem of rectangular plates with stepped thickness resting on non-homogeneous elastic foundations. The unknown quantities of the method exist only on half of the boundary. The non-homogeneous elastic foundation discussed here consists of two-segment elastic Winkler foundation. The fundamental differential equations are established for the bending problem of the plate on elastic foundations. The Green function, which is obtained by transforming these differential equations into integral equations and using numerical integration, is used to establish the characteristic equation of the free vibration. The effects of the modulus of the foundation, the stepped thickness and aspect ratio on the frequency parameters are considered. By comparing the present numerical results with those previously published, the efficiency and accuracy of the present method are investigated.
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Existing bridge structural identification by vibration measurements using Laser Doppler Velocimeter 査読あり
Makino K., Morita C., Matsuda H., Sumitro P., Yanai S.
Bridge Maintenance, Safety, Management, Resilience and Sustainability - Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management 2190 - 2196 2012年7月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：Bridge Maintenance, Safety, Management, Resilience and Sustainability - Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management
Nowadays in Japan, there is an increasing demand to investigate those suspicious structural-degraded-bridges which were constructed in 1970s. In common, those bridges are investigated by simple inspections such as visual inspections and hammer tests. Cons of the above mentioned method are less-objective, accuracy insufficiency and lack of promptness. Moreover, there are some difficulties to evaluate current load carrying capacity and earthquake resistance of aging-bridges due to unavailability of design drawings. Thus, the vibration measurement method is utilized simply to evaluate bridge's structural performance. Structural properties are mainly influenced by fatigue, material deterioration and earthquakes. These factors cause the changes of characteristic frequency due increasing of lateral displacement and decreasing of stiffness. Therefore, damage identification of a structure can be assessed by grasping its vibrational property. Conventional vibration measurement was generally conducted by using accelerometers. This consumed a lot time for cabling, installation and dismantling sensors and cable, and rather than that, efficiency and safety issues remained, especially, in case of installation at dangerous spots during a post-disaster or emergency events. In view of above mentioned problems related to conventional measurement, a long distance, non-contact, and easily-assembled LDV (Laser Doppler Velocimeter) has been developed in recent years. Without requiring on-structure sensor installation and having huge flexibility under variety of measurement environments made LDV measurement technique attractive and to be considered as better than other non-destructive investigation methods. This study targeted in-service bridges by measuring their natural frequencies and displacements using two LDV devices. Measuring numerous spots with two LDV devises enables to achieve high accuracy and reliability to verify the most-scrutinized structural vibration mode shape. Furthermore, the field-measured-based analyzed results were compared with three-dimensional FEM model analyses to evaluate the validity of the analytical model and to grasp the structural vibration characteristics of measured-bridges. © 2012 Taylor & Francis Group.
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Study on failure characteristic of rock-like materials with an open-hole under uniaxial compression 査読あり
Zhao C., Matsuda H., Morita C., Shen M.
Strain 47 ( 5 ) 405 - 413 2011年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Strain
The failure strength model of brittle materials with a pre-existing open-hole defect is proposed in this paper. A modified Sammis-Ashby model is deduced, in which it can be used to calculate the peak strength of brittle materials. It shows the law between peak strength Ïpand independent variable Î, which is the ratio of open-hole radius (a) to half-width of the specimen (t). Moreover, numerical and experimental investigations on failure process of rock-like materials with an open-hole imperfection were carried out. In the experiments, 3D-digital image correlation method, an optical technique which utilises the full-field and non-contact measurement, was employed. A progressive elastic damage method realistic failure process analysis (RFPA) was used in the numerical investigation to inspect and verify the modified model and simulate the failure process. The investigation finds that there are good correlations between the experimental, numerical and theoretical results. Moreover, because of the influences of boundary conditions, shear failure type was obtained both experimentally and numerically. © 2010 Blackwell Publishing Ltd.
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Morita C., Zhao C., Demizu A., Makino K., Matsuda H., Ichimiya K.
Bridge Maintenance, Safety, Management and Life-Cycle Optimization - Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management 2550 - 2556 2010年12月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：Bridge Maintenance, Safety, Management and Life-Cycle Optimization - Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management
Cylindrical shells are widely used in the most diverse branches of civil engineering technologies because of they combine light weight with high strength. However the buckling strength and postbuckling behavior prediction are extremely complex especially for thin-walled ones. Initial geometric imperfections are normally known to have a strong detrimental on the buckling strength and to be the reason of large discrepancy between experimental buckling loads and theoretical predictions. Moreover random imperfections in real shells are not known at the stage of design and may take a complex form. In order to investigate the effects of geometric imperfections on the buckling strength and post-buckling phenomena of thinwalled cylinders, these investigations were carried out both experimentally and numerically. In present paper, a general and simple approach is proposed for modeling the geometric imperfection of thin-walled shell specimens by utilizing 3-D digital image correlation method (DICM), an optical non-contact and full-field measurement. Realistic geometric imperfection of thin-walled shell specimens were obtained and applied in numerical simulation, the thickness of specimens used in this experiment is 0.131mm and the ratio of external diameter (R) to thickness (H) R/H is 250. Procedures of scanning on the geometric imperfection of thin-walled shell specimen and its application in numerical simulation are described detailed in this paper. The experimental investigation agrees well with the numerical simulation on both the strength and buckling behaviours. Therefore by using this effective approach the potential of strength capacity can be tapped in real thin-walled shell structures and it is demonstrated the visualization of buckling behaviors with initial random geometric imperfections by using this digital image correlation technique. © 2010 Taylor & Francis Group, London.
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Free vibration analysis of continuous rectangular plates 査読あり
Huang M., Ma X., Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 329 ( 4 ) 485 - 496 2010年2月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
Vibration characteristics of rectangular plates continuous over full range line supports or partial line supports have been studied by using a discrete method. Concentrated loads with Heaviside unit functions and Dirac delta functions are used to simulate the line supports. The fundamental differential equations are established for the bending problem of the continuous plate. By transforming these differential equations into integral equations and using the trapezoidal rule of the approximate numerical integration, the solution of these equations is obtained. Green function which is the solution of deflection of the bending problem of plate is used to obtain the characteristic equation of the free vibration. The effects of the line support, the variable thickness and aspect ratio on the frequencies and mode shapes are considered. By comparing the numerical results obtained by the present method with those previously published, the efficiency and accuracy of the present method are investigated. © 2009.
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Natural vibration study on rectangular plates with a line hinge and various boundary conditions 査読あり
Huang M., Ma X., Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 322 ( 1-2 ) 227 - 240 2009年4月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
A discrete method is proposed for analyzing the natural vibration problem of rectangular plates with a line hinge. The fundamental differential equations and the solutions of these equations are derived for two parts of the plate, which are obtained by dividing the plate along the line hinge. By transforming these equations into integral equations, and using numerical integration and the continuous conditions along the line hinge, the solutions of the whole plate can be expressed by the unknown quantities on the boundary and the quantities of the rotation along the hinge. The Green function of the deflection problem is used to obtain the characteristic equation of the free vibration. The effects of the position of the line hinge, the aspect ratio, the thickness ratio and the boundary condition on the natural frequency parameters are considered. By comparing the numerical results obtained by the present method with those previously published, the efficiency and accuracy of the present method are investigated. © 2008 Elsevier Ltd. All rights reserved.
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Buckling and post-bucklin phenomena of cylindrical shell under axail compression and torsion loading 査読あり
Zhao C., Matsida H., Morita C., Huang M.
EASEC-11 - Eleventh East Asia-Pacific Conference on Structural Engineering and Construction 2008年12月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：EASEC-11 - Eleventh East Asia-Pacific Conference on Structural Engineering and Construction
In order to investigate the buckling and post-buckling phenomena of thin-walled cylindrical shells, these experiments were carried out by using Digital Image Correlation Method (DIC). The tested specimens have a thickness of 0.131mm and the ratio of external diameter (R) to thickness (H) R/H is 252. DICM is an optical instrument which utilizes the full-field and non-contact measurement to gauge the three-dimensional displacement and strains on materials and structural components. DICM has been proven to be a flexible and useful tool for deformation analysis. In this paper, DIC system, with two high resolution digital cameras, is applied to observe the buckling generation process in details and make a record of the surface displacements during the tests of cylindrical shell subjected to axial compression and torsion loading, and displacements are obtained and shown in color contour in full field region. The experimental study shows that visualization of buckling behaviors on thin-walled cylindrical shells by using DIC techniques is potential. Typical full-field strain patterns from the buckling tests are obtained both of compression test and torsion test. Test results are compared and discussed in present paper.
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Ma X., Morita C., Sakiyaina T., Matsuda H., Huang M.
Advances in Heterogeneous Material Mechanics 2008 - Proceedings of the 2nd International Conference on Heterogeneous Material Mechanics, ICHMM 2008 1555 - 1558 2008年11月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：Advances in Heterogeneous Material Mechanics 2008 - Proceedings of the 2nd International Conference on Heterogeneous Material Mechanics, ICHMM 2008
The objective of this paper is to clarify the characteristics of vibration of plates with variable thickness and with a hole defect by analytical and experimental methods. The vibration frequencies and modes obtained by proposed discrete method are verified with the experimental results. Moreover, the effects of the thickness of plates, size of the defect on free vibration behavior of plates are shown.
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Free vibration analysis of rectangular plates with variable thickness and point supports 査読あり
Huang M., Ma X., Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 300 ( 3-5 ) 435 - 452 2007年3月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
A discrete method is developed for analyzing the free vibration problem of rectangular plates with point supports. The fundamental differential equations involving Dirac's delta function are established for the bending problem of the plate with point supports. By transforming these differential equations into integral equations and using numerical integration, the solution of these equations is obtained and used as Green function to obtain the characteristic equation of the free vibration. The effects of the point support, the boundary condition, the variable thickness and aspect ratio on the frequencies are considered. By comparing the numerical results obtained by the present method with those previously published, the efficiency and accuracy of the present method are investigated. © 2005 Elsevier Ltd. All rights reserved.
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Performance of weathering steel in bridges in kyushu-yamaguchi region 査読あり
Yamaguchi E., Nakamura S., Hirokado K., Morita C., Sonoda Y., Aso T., Watanabe H., Yamaguchi K., Iwatsubo K.
Doboku Gakkai Ronbunshuu A 62 ( 2 ) 243 - 254 2006年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Doboku Gakkai Ronbunshuu A
Many weathering steel bridges have been constructed in recent years. However, the performance of the steel in those bridges is not well traced and so little known. Against this background, "Committee on the Performance of Weathering Steel Bridges in Kyushu-Yamaguchi Region" in Kyushu Association for Bridge and Structural Engineering (KABSE) , conducted the filed study of performance of weathering steel in bridges in the region. This paper describes the result of this study, based on which the factors that may influence the rust development are also discussed.
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Huang M., Ma X., Sakiyama T., Matuda H., Morita C.
Journal of Sound and Vibration 288 ( 4-5 ) 931 - 955 2005年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
A discrete method is developed for analyzing the free vibration problem of orthotropic rectangular plates with variable thickness. The Green function, which is obtained by transforming the differential equations into integral equations and using numerical integration, is used to establish the characteristic equation of the free vibration. The effects of the aspect ratios, boundary conditions, the variation of the thickness on the frequencies are considered. By comparing the numerical results obtained by the present method with the those previously published, the efficiency and accuracy of the present method are investigated. The frequency parameters are obtained for the orthotropic plates with general boundary conditions and variable thickness in one or two directions. The model shapes are given for some of the square plates with three kinds of thickness variations. © 2005 Elsevier Ltd. All rights reserved.
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Vibration analysis of twisted plates using first order shear deformation theory 査読あり
Hu X., Sakiyama T., Xiong Y., Matsuda H., Morita C.
Journal of Sound and Vibration 277 ( 1-2 ) 205 - 222 2004年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
Based on general shell theory and the first order shear deformation theory, an accurate relationship between strains and displacements of a twisted plate is derived by the Green strain tensor. An equation of equilibrium for free vibration is given by the principle of virtual work and the governing equation is solved by using the Rayleigh-Ritz method with sets of orthonormal polynomials in which only the first polynomials are defined according to the geometric boundary conditions of a plate and the others are generated by the Gram-Schmidt process. The numerical verification is carried out by comparing with previous results of cantilever plates. Vibration characteristics of cantilever twisted plates such as frequency parameters and corresponding mode shapes are obtained by the present numerical method, and the effects of the twist angle, the aspect ratio and the thickness ratio on them are studied. © 2003 Elsevier Ltd. All rights reserved.
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Fundamental vibration of rotating cantilever blades with pre-twist 査読あり
Hu X., Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 271 ( 1-2 ) 47 - 66 2004年3月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
A non-linear strain-displacement relationship of a pre-twisted conical shell on the general shell theory is utilized, and a method for vibration of a rotating cantilever conical shell with pre-twist is developed by the principle of virtual work and the Rayleigh-Ritz method. Firstly, deformation and stress resultants caused by rotation are analyzed. Secondly, an equilibrium of energy for vibration of a pre-twisted conical shell having the conditions achieved in the first process is given and then an eigenfrequency equation of a rotating cantilever conical shell with pre-twisted is formulated. The effects of parameters such as an angular velocity, a radius of a hub, a setting angle, a twist angle, a subtended angle and a tapered ratio of cross-section on the fundamental vibration are investigated. © 2003 Elsevier Ltd. All rights reserved.
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Vibration of angle-ply laminated plates with twist by Rayleigh-Ritz procedure 査読あり
Hu X., Sakiyama T., Lim C., Xiong Y., Matsuda H., Morita C.
Computer Methods in Applied Mechanics and Engineering 193 ( 9-11 ) 805 - 823 2004年3月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Computer Methods in Applied Mechanics and Engineering
Considering transverse strain and rotary inertia, an analytical method for vibration of an angle-ply laminated plate with twist is proposed. An accurate strain-displacement relationship of a twisted plate is derived by the Green strain tensor on the general shell theory and the Mindlin plate theory. The equilibrium for free vibration is given out by the principle of virtual work and is solved by using the Rayleigh-Ritz procedure with normalized characteristic orthogonal polynomials generated by the Gram-Schmidt process. The convergence and the accuracy of the present method are investigated. The parametric effects of a fibre angle, a twist angle, a thickness ratio and a stacking sequence on vibration frequencies and mode shapes of laminated plates are studied. © 2003 Elsevier B.V. All rights reserved.
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Ario I., Morita C., Suyama H., Sato E., Fujii K.
Nippon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A 69 ( 1 ) 148 - 153 2003年1月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Nippon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
We suppose that most organisms have the optimized structures under various environment, but its mechanism has the most complex and many unknown factors. In this paper, we propose that it is useful in engineering to obtain the mechanism of a bamboo structure using the laminate sheet model, through the experiments and the observation of the organizational structure within fibers of a bamboo. Based on the fundamental research of the fiber contents and strength of the bamboo's slices, we could learn how to construct the more fiber or the laminated composite structures by numerical analysis of the elastic-plastic FEM. This paper denoted that it is applicable to obtain the organizational properties of bamboo by the laminate sheet model.
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Free vibration of orthotropic square plates with a square hole 査読あり
Sakiyama T., Huang M., Matsuda H., Morita C.
Journal of Sound and Vibration 259 ( 1 ) 63 - 80 2003年
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
An approximate method is extended for analyzing the free vibration problem of orthotropic square plate with a square hole. In this paper, a square plate with a square hole is transformed into an equivalent square plate with non-uniform thickness by considering the hole as an extremely thin part of the equivalent plate. Therefore, the dynamic characteristics of a plate with a hole can be obtained by analyzing the equivalent plate. The Green function, which is the discrete solution for the deflection of the equivalent plate, is used to obtain the characteristic equation of the free vibration. The effects of the side to thickness ratio, hole side to plate side ratio and the variation of the thickness on the frequencies are considered. Some numerical analyses are carried out for the simply supported orthotropic square plate with a square hole. The efficiency and accuracy of the numerical solutions by the present method are investigated. © 2002 Elsevier Science Ltd. All rights reserved.
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Free vibration analysis of orthotropic right cantilever triangular plates 査読あり
Sakiyama T., Huang M., Matsuda H., Morita C.
Journal of Sound and Vibration 259 ( 1 ) 219 - 228 2003年
記述言語：英語 掲載種別：研究論文（学術雑誌）
An approximate method was proposed for the free vibration of orthotropic right cantilever triangular plate with various aspect ratios and variable thickness. An equivalent rectangular was used to replace the right triangular plate in the free vibration analysis. Based on the Green function of the equivalent rectangular plate, the characteristic equation of free vibration was obtained. The results showed that the numerical solutions obtained by the proposed method had good convergence and satisfactory accuracy.
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Vibration analysis of rotating twisted and open conical shells 査読あり
Hu X., Sakiyama T., Matsuda H., Morita C.
International Journal of Solids and Structures 39 ( 25 ) 6121 - 6134 2002年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Journal of Solids and Structures
Based on a non-linear strain-displacement relationship of a non-rotating twisted and open conical shell on thin shell theory, a numerical method for free vibration of a rotating twisted and open conical shell is presented by the energy method, where the effect of rotation is considered as initial deformation and initial stress resultants which are obtained by the principle of virtual work for steady deformation due to rotation, then an energy equilibrium of equation for vibration of a twisted and open conical shell with the initial conditions is also given by the principle of virtual work. In the two numerical processes, the Rayleigh-Ritz procedure is used and the two in-plane and a transverse displacement functions are assumed to be algebraic polynomials in two elements. The effects of characteristic parameters with respect to rotation and geometry such as an angular velocity and a radius of rotating disc, a setting angle, a twist angle, curvature and a tapered ratio of cross-section on vibration performance of rotating twisted and open conical shells are studied by the present method. © 2002 Elsevier Science Ltd. All rights reserved.
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Vibration of cantilevered laminated composite conical shells with twist 査読あり
Sakiyama T., Hu X., Matsuda H., Morita C.
High Performance Structures and Materials 4 47 - 55 2002年12月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス） 出版者・発行元：High Performance Structures and Materials
Considering an accurate relationship between strains and displacements derived on the thin shell theory for twisted thin conical shells, a method for analyzing the vibrations of twisted conical shells made up of laminated composite materials is presented, in which the principle of virtual work for free vibrations and the Rayleigh-Ritz procedure with algebraic polynomials in two elements as displacements are adopted. The effects of the number of laminae, the fiber orientation, the twist, the taper ratio and the subtended angle on the vibration characteristics of cantilevered laminated composite conical shells are studied by the present method.
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Vibration analysis of twisted conical shells with tapered thickness 査読あり
Hu X., Sakiyama T., Matsuda H., Morita C.
International Journal of Engineering Science 40 ( 14 ) 1579 - 1598 2002年8月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Journal of Engineering Science
Considering twisted conical shells with tapered thickness, a numerical method for analyzing free vibration is developed, where an exact strain-displacement relationship of twisted conical shells is derived based on the shell theory, the equation of energy equilibrium for free vibration is formulated by the principle of virtual work, and the governing equation is obtained by the Rayleigh-Ritz procedure. The convergent property is investigated in view of the assumed displacement functions, and the comparison between the present and the available previous results for several typical conical shells is carried out in order to demonstrate the practicability and the accuracy. The effects of the tapered thickness in two directions, the twist angle, the subtended angle and the taper ratio of cross-section on the vibration behavior are discussed through the frequencies and corresponding mode shapes. © 2002 Published by Elsevier Science Ltd.
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Vibration of twisted laminated composite conical shells 査読あり
Hu X., Sakiyama T., Matsuda H., Morita C.
International Journal of Mechanical Sciences 44 ( 8 ) 1521 - 1541 2002年8月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Journal of Mechanical Sciences
A methodology for free vibration of a laminated composite conical shell with twist is proposed, in which a strain-displacement relationship of a twisted conical shell is given by considering the Green strain tensor on the general thin shell theory, the principle of virtual work is utilized, and the governing equation is formulated by the Rayleigh-Ritz procedure with algebraic polynomials in two elements as admissible displacement functions. The convergence, the accuracy and the validity of the methodology are verified by comparisons. As a result of the vibration frequencies and mode shapes, the effects of the laminated constructional and the geometric parameters, such as the number of laminae, the fiber orientation angles, the twist angle, the subtended angle and the taper ratio, on the vibration characteristics are studied by the present methodology. © 2002 Elsevier Science Ltd. All rights reserved.
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Vibration of twisted and curved cylindrical panels with variable thickness 査読あり
Sakiyama T., Hu X., Matsuda H., Morita C.
Journal of Sound and Vibration 254 ( 3 ) 481 - 502 2002年7月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
A numerical procedure, with an exact strain-displacement relationship of twisted and curved cylindrical panels having variable thickness derived by considering the Green strain tensor on general shell theory, is presented using the principle of virtual work and the Rayleigh-Ritz method with algebraic polynomials as in-plane and transverse displacement functions. The accuracy and applicability of the procedure are verified by comparing the present results with previous experimental and theoretical results for several panels. The effects of variation ratio of thickness in chordwise and lengthwise directions, twist, and curvature both in two directions aforementioned on vibrations of cylindrical panels are studied in detail, and typical vibration mode shapes are plotted to demonstrate the effects.
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Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 203 ( 3 ) 505 - 522 1997年6月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
In this paper, a method of analysis for the free vibration of a three-layer sandwich arch with an elastic or viscoelastic core, and with various kinds of axis-shape and boundary conditions is presented. The characteristic equation of the free vibration is derived by applying Green functions. The Green functions are obtained in a discrete form for various kinds of sandwich arches with non-uniform cross-section and radius of curvature. They enable the setting up of the frequency equation in eigenvalue form. © 1997 Academic Press Limited.
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Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 198 ( 4 ) 439 - 454 1996年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
In this paper, an analytical method for the free vibration of a three-layer, continuous sandwich beam with an elastic or viscoelastic core and arbitrary boundary conditions is presented. The characteristic equation for finding the natural frequencies and modes is derived by introducing a discrete-type Green function which is a discrete solution of the differential equation governing the flexural behaviour of a sandwich beam under the action of a concentrated load. The Green function can be obtained equally for a beam with a non-uniform cross-section as well as a beam with uniform cross-section, and it enables the setting up of the frequency equation in eigenvalue form, so that the free vibration of the beam can be analysed efficiently without any calculation using a trial and error method. The numerical solution is shown to have a uniform convergency and good accuracy, and some effects of varying the elastic or viscoelastic core shear modulus and depths of core on the natural frequency and loss factor of a continuous sandwich beam are evaluated. © 1996 Academic Press Limited.
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Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 191 ( 2 ) 189 - 206 1996年3月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
A method of analysis of the free vibration of a three-layer sandwich beam with an elastic or viscoelastic core and arbitrary boundary conditions is presented. The characteristic equation of the free vibration is derived by applying the Green function which is obtained as a discrete solution of differential equations governing the flexural behaviour of the sandwich beam under the action of a concentrated load. By applying the characteristic equation, the behaviour of the free vibration of the sandwich beam with an elastic or viscoelastic core can be analyzed efficiently without a calculation by a trial and error method. It is shown that the numerical solution has uniform convergence and good accuracy, and the effect of the elastic or viscoelastic core shear modulus and the depth of the core on the natural frequency and the loss factor of the sandwich beam are evaluated. © 1996 Academic Press Limited.
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A FREE VIBRATION ANALYSIS OF ANISOTROPIC RECTANGULAR PLATES WITH VARIOUS BOUNDARY CONDITIONS 査読あり
Morita C., Matsuda H., Sakiyama T., Hagino T.
Journal of Sound and Vibration 187 ( 5 ) 757 - 770 1995年11月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
An approximate method in which discrete Green functions are used is described for analyzing the free vibration of anisotropic rectangular plates with various boundary conditions. The discrete Green functions are obtained by transforming the differential equations involving Dirac's delta functions into integral equations and numerically integrating them. By employing these discrete Green functions, the differential equations governing the free vibration of anisotropic rectangular plates are transformed into the equivalent boundary integral equations, which are then solved to obtain the eigenvalues and eigenmodes. Comparisons with existing results confirm the accuracy of the numerical solutions obtained by the method. Results are presented for anisotropic rectangular plates with a number of combinations of clamped and simply supported edges and various angles of fiber orientation. © 1995 Academic Press. All rights reserved.
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In-plane and out-of-plane free vibrations of curved beams with variable sections 査読あり
Kawakami M., Sakiyama T., Matsuda H., Morita C.
Journal of Sound and Vibration 187 ( 3 ) 381 - 401 1995年11月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
We present an approximate method to study the analysis for both the in-plane and out-of-plane free vibration of horizontally curved beams with arbitrary shapes and variable cross-sections. The characteristic equation for free vibration can be derived by applying the Green function, which is obtained as a discrete type solution of differential equations governing the flexural behaviour of the curved beam under the action of a concentrated load. © 1995 Academic Press Ltd.
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Longitudinal impulsive response analysis of variable cross-section bars 査読あり
Matsuda H., Sakiyama T., Morita C., Kawakami M.
Journal of Sound and Vibration 181 ( 3 ) 541 - 551 1995年3月
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Matsuda H., Morita C., Sakiyama T.
Journal of Sound and Vibration 158 ( 2 ) 331 - 339 1992年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Sound and Vibration
An approximate method is developed to study the bending vibration of a tapered Timoshenko beam with constraint at any points and carrying a heavy tip body. The solutions are obtained by transforming the ordinary differential equations into integral equations and integrating them numerically. As applications of this method, some numerical examples are shown. © 1992.
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Analysis on geometrical nonlinear behavior of rectangular plates 査読あり
Morita C., Matsuda H., Sakiyama T.
Structural Engineering/Earthquake Engineering 9 ( 3 ) 35 - 43 1992年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Structural Engineering/Earthquake Engineering
In this paper, a discrete method for analyzing the geometrical nonlinear problems of rectangular plates is proposed. The solutions of partial differential equations of rectangular plates are obtained in discrete forms by applying the numerical integration, and they give the transverse shear forces, twisting moment, bending moments, rotations, deflection, in-plane displacements and membrane forces at all discrete points. The nonlinear problems are solved by the iteration and the load incremental procedure. As the applications of the present method, geometrical nonlinear bending and post-buckling problems of rectangular plates with some of boundary conditions are calculated.
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An approximate method for analyzing tapered mindlin plates 査読あり
Matsuda H., Morita C., Sakiyama T.
Computers and Structures 43 ( 1 ) 185 - 191 1992年4月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Computers and Structures
An approximate method is developed to study the static bending of tapered Mindlin plates. The solutions are obtained by representing the partial differential equations into the ordinary differential equations by means of the Fourier series and by transforming the ordinary differential equations into integral equations and applying the numerical integrations. Some numerical examples are shown together with other analytical solutions, and as an application of this method, the results of tapered Mindlin plate are shown. © 1992.
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An approximate method of shallow shells with variable thickness 査読あり
Matsuda H., Morita C., Sakiyama T.
Computers and Structures 42 ( 6 ) 989 - 996 1992年3月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Computers and Structures
An approximate method is developed to study the static bending of shallow shells with variable thickness. The solutions are obtained by transforming the partial differential equations into the integral equations and applying the numerical integrations. Some numerical examples are shown together with other solutions, and as an application of this method, the results of shallow shell with variable thickness are shown. © 1992.
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Geometrical nonlinear analysis of rectangular mindlin plates 査読あり
Matsuda H., Morita C., Sakiyama T.
Computers and Structures 41 ( 4 ) 869 - 874 1991年
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Computers and Structures
An approximate method is developed to study the geometrical nonlinear analysis of the rectangular plates. The solutions are obtained by transforming the partial differential equations into the integral equations and applying the numerical integrations. The nonlinear problem is solved by the iteration and the load incremental procedure. The results are compared with FE-solutions. © 1991.
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Fundamental frequency factors of skew plates with mixed boundary conditions 査読あり
Matsuda H., Sakiyama T., Morita C.
Journal of Sound and Vibration 136 ( 3 ) 519 - 521 1990年2月
記述言語：英語 掲載種別：研究論文（学術雑誌）