Inverse identification of plastic anisotropy through multiple non-conventional mechanical experimentsZhang, Y.; Yamanaka, A.; Cooreman, S.; Kuwabara, T.; Coppieters, S.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
PERGAMON-ELSEVIER SCIENCE LTD
In theory, a single non-conventional mechanical experiment generating inhomogeneous strain fields enables to inversely identify an anisotropic yield function. However, several studies have shown that it is challenging to design such a sufficiently data-rich experiment, particularly when it must be conducted on a standard uniaxial tensile machine. Instead of relying on a single non-conventional uniaxial tensile experiment, combining multiple non-conventional experiments is proposed to inversely identify an advanced anisotropic yield function. The feasibility of the proposed method is verified through the inverse identification of the Yld2000-2d yield function using synthetically generated Digital Image Correlation (DIC) data. This approach accounts for the metrological aspects of DIC while avoiding potential experimental errors and uncertainties related to the selected material model. It has been demonstrated that when a single non-conventional tensile test is combined with a non conventional biaxial tensile test, the inversely identified anisotropy parameters are in good agreement with those found through the conventional method. This finding is contingent on maintaining an equal contribution of the strain states from each experiment to the cost function. Excluding overlapping data points and assigning proper weights to the trustworthy data based on the strain state and the level of plastic deformation is found to be key. The numerical results are experimentally validated, thereby revealing the crucial role of the adopted anisotropic yield function. Furthermore, the uncertainty associated with the inversely identified parameters based on three repetitions of the same experiment is discussed.
2023年12月15日, 研究論文(学術雑誌), 共同, 285, 0020-7683,
DOI(公開)(r-map) Application of Bayesian Optimization to the Synthesis Process of BaFe2(As,P)2 Polycrystalline Bulk Superconducting MaterialsAkimitsu Ishii, Shinjiro Kikuchi, Akinori Yamanaka, Akiyasu Yamamoto
Journal of Alloys and Compounds
ELSEVIER SCIENCE SA
This study is the first application of Bayesian optimization to the synthesis process of superconducting materials. As a model case, the phase purity of BaFe2(As,P)2 polycrystalline bulks, which affects their superconducting properties, was improved by optimizing only the heat-treatment temperature using Bayesian optimization. We determined the optimal temperature among 800 candidates in 13 experiments, and a phase purity of 91.3 % was achieved. Moreover, the phosphorus doping level of the best sample approached the optimal doping level owing to a reduction in the impurity phase. Visualization of the Bayesian optimization process showed that a well-balanced global search and local optimization allowed us to obtain a rough correlation between the super-conducting properties and experimental conditions and finely optimal experimental conditions over a wide range. These results demonstrate that Bayesian optimization is promising for optimizing the synthesis process of superconducting materials.
2023年12月05日, 研究論文(学術雑誌), 共同, 996, 0925-8388,
DOI(公開)(r-map), 171613
Inverse characterization of a material model using an ensemble-based four-dimensional variational methodSae Sueki, Akimitsu Ishii, Sam Coppieters, Akinori Yamanaka
International Journal of Solids and Structures
PERGAMON-ELSEVIER SCIENCE LTD
The identification accuracy of material model parameters is essential for accurately predicting the deformation behavior of metallic materials (e.g., metal forming) using a finite element (FE) simulation. Numerous researchers have studied inverse material model characterization, where parameters are determined by minimizing a cost function that quantifies the difference between experimental data and mechanical test simulation results. However, sensitivity analysis in the optimization process hinders the extensibility of inverse methods due to issues like computational cost and complex numerical implementation. In this study, we developed a novel inverse methodology for material model characterization that improves extensibility by applying an ensemble based four-dimensional variational method (En4DVar), which has the potential to address the challenges associated with conventional FE-based inverse material model characterization. The developed method was verified through numerical experiments in which En4DVar was applied to an elastoplastic FE simulation of the deformation of an aluminum alloy during a uniaxial tensile test, including diffuse necking. We investigated the estimation accuracy of the strain-hardening parameters in Swift's hardening law and evaluated the simulation results under various conditions through numerical experiments. We focused on the effect of time and location to incorporate synthetic experimental data into the simulation to examine the quantities of synthetic experimental data required for parameter estimation. The results of the numerical experiments showed that En4DVar is a powerful approach for estimating the parameters and characterizing the deformation behavior of a material. Moreover, it was shown that accurate estimation results can be obtained even using synthetic experimental data with a relatively low temporal resolution or a small field of view. The proposed method's ease of extensibility using En4DVar expands the range of problems solvable in the field of material model characterization.
2023年09月01日, 研究論文(学術雑誌), 共同, 279, 0020-7683,
DOI(公開)(r-map), 112350
DMC-TPE: Tree-Structured Parzen Estimator-Based Efficient Data Assimilation Method for Phase-Field Simulation of Solid-State SinteringAkimitsu Ishii, Akiyasu Yamamoto, Akinori Yamanaka
Science and Technology of Advanced Materials: Methods
2023年07月28日, 研究論文(学術雑誌), 共同, 3,
DOI(公開)(r-map), 2239133
Modulated structure formation in dislocation cells in 316L stainless steel fabricated by laser powder bed fusionFei Sun, Toshio Ogawa, Yoshitaka Adachi, Kazuhisa Sato, Shunya Takagi, Goro Miyamoto, Asuka Suzuki, Akinori Yamanaka, Nobuo Nakata, Yuichiro Koizumi
MATERIALS TRANSACTIONS
2023年06月01日, 研究論文(学術雑誌), 共同, 64, 6,
DOI(公開)(r-map), 1143, 1149
Phase-field Modeling of Solid-state Sintering with Interfacial AnisotropyAkimitsu Ishii, Kyoyu Kondo, Akiyasu Yamamoto, Akinori Yamanaka
Materials Today Communications
ELSEVIER
Sintered structures observed in experiments can consist of faceted crystal grains. To predict the formation of such structures, a new phase-field (PF) model of solid-state sintering that can analyze morphological changes and microstructural evolutions considering the strong interface anisotropies of sintered particles was developed in this study. The developed PF model treats the crystal grain orientation-dependent surface and misorientationdependent grain boundary anisotropies. Furthermore, this model employs quaternions to calculate the particle rotation, eliminating complicated calculations involved in analyzing the crystal orientation in three-dimensional (3D) simulations. The morphological change in a sintered particle and the grain boundary formulation at triple junctions simulated using the developed model were validated by comparing them with theoretical solutions. The neck growth and densification rates were investigated by performing 3D simulations using two particles with interface anisotropies. The simulation results revealed that neck growth and densification are affected by surface energy and mobility anisotropies. A 3D PF simulation using 200 particles demonstrated that the developed PF model can potentially reproduce sintered structures with faceted particles observed in experiments. The PF model provides a promising simulation for predicting the microstructural evolution of actual materials during solid-state sintering.
2023年06月, 研究論文(学術雑誌), 共同, 35,
DOI(公開)(r-map), 106061
Big-volume SliceGAN for improving a synthetic 3D microstructure image of additive-manufactured TYPE 316L steelKeiya Sugiura, Toshio Ogawa, Yoshitaka Adachi, Fei Sun, Asuka Suzuki, Akinori Yamanaka, Nobuo Nakada, Takuya Ishimoto, Yuichiro Koizumi, Takayoshi Nakano
Journal of Imaging
A modified SliceGAN architecture was proposed to generate a high-quality synthetic three-dimensional (3D) microstructure image of TYPE 316L material manufactured through additive methods. The quality of the resulting 3D image was evaluated using an auto-correlation function, and it was discovered that maintaining a high resolution while doubling the training image size was crucial in creating a more realistic synthetic 3D image. To meet this requirement, modified 3D image generator and critic architecture was developed within the SliceGAN framework.
2023年04月29日, 研究論文(学術雑誌), 共同, 9,
DOI(公開)(r-map), 90
Multi-Phase-Field Simulation of Non-Equilibrium Solidification in 316L Stainless Steel under Rapid Cooling ConditionMasahito Segawa, Akinori Yamanaka
Materials Transactions
Additive manufacturing has attracted much attention as a new technology for producing lightweight and high-strength materials. The multi-phase-field method has been used in powerful numerical simulations to predict solidification microstructure formation in additive manufacturing. To verify the non-equilibrium multi-phase-field (NEMPF) model that can consider strong out-of-equilibrium solid/liquid interfacial conditions, the NEMPF model coupled with the CALPHAD-based thermodynamic database was used to simulate the solidification process in 316L stainless steel (SS) under a rapid cooling condition. The results show that interstitial carbon atoms tend to segregate at the solid/liquid interface, whereas no concentration gradient is observed at the grain boundary between the solid phases. Conversely, substitutional Cr, Mo, and Mn atoms were segregated in the solid grain boundaries. The effects of interfacial mobility and interfacial permeability on the solidification behavior were investigated. The results show that these parameters strongly influence the solidification rate and distribution of the solute concentration at the solid/liquid interface. [doi:10.2320/matertrans.MT-ME2022013]
2023年, 研究論文(学術雑誌), 共同, 64, 6, 1345-9678,
DOI(公開)(r-map), 1160, 1168
Phase-field modeling and simulation of solid-state phase transformations in steelsAkinori Yamanaka
ISIJ International
IRON STEEL INST JAPAN KEIDANREN KAIKAN
The phase-field method is used as a powerful and versatile computational method to simulate the microstructural evolution taking place during solid-state phase transformations in iron and steel. This review presents the basic theory of the phase-field method and reviews recent advances in the phase-field modeling and simulation of solid-state phase transformations in iron and steel, with particular attention being paid to the modeling of the austenite-to-ferrite, pearlitic, bainitic, and martensitic transformations. This review elucidates that the phase-field method is a promising computational approach to investigate the microstructural evolutions (e.g., interface migration, solute diffusion, and stress/strain evolutions) that take place during the phase transformations. It also indicates that further improvements are required to enhance the predictive accuracy of the phase-field models developed to date. Finally, this review discusses the critical challenges and perspectives for the further improvement of the phase-field modeling of solidstate phase transformations in steel, i.e., the modeling of heterogeneous nucleation, the abnormal effect of the diffusion interface, and material parameter identification.
2023年, 研究論文(学術雑誌), 単独, 63, 3, 0915-1559,
DOI(公開)(r-map), 395, 406
Three-dimensional microstructure and critical current properties of ultrafine grain Ba(Fe,Co)2As2 bulk superconductorsYusuke Shimada, Shinnosuke Tokuta, Akinori Yamanaka, Akiyasu Yamamoto, Toyohiko J Konno
Journal of Alloys and Compounds
ELSEVIER SCIENCE SA
In iron-based superconductors, randomly oriented grain boundaries have a strong influence on the trans-port properties via intrinsic weak-link and flux pinning mechanisms. Herein we report the critical current density (J(c)) and the three-dimensional microstructure of polycrystalline bulk Co-doped Ba122 (BaFe1.84Co0.16As2) superconductors, with highly dense grain boundaries (grain size smaller than 50 nm), produced by high-energy milling. Three-dimensional electron microscopy revealed that the anomalous growth of secondary particles (aggregation) and the inter-aggregation structures were significantly different in the samples with finer grains, which may have extrinsically limited J(c). These important micro-structural features were quantified as two parameters-local thickness and total pore length-by reconstructing the three-dimensional structure of the superconducting phase using the adaptive thresh-olding method. The results obtained in this study suggest that understanding and controlling the micro-structural formation process by sintering are instrumental for improving the J(c) properties of 122 polycrystalline materials consisting of ultrafine grains. (c) 2022 Elsevier B.V. All rights reserved.
2022年11月25日, 研究論文(学術雑誌), 共同, 923, 0925-8388,
DOI(公開)(r-map), 166358
Validating a mean-field theory via large-scale phase-field simulations for abnormal grain growth induced by nonuniform grain boundary propertiesEisuke Miyoshi, Munekazu Ohno, Yasushi Shibuta, Akinori Yamanaka, Tomohiro Takaki
Journal of Materials Science
SPRINGER
The mean-field theory proposed by Humphreys is widely used to predict or interpret abnormal grain growth induced by nonuniform grain boundary properties. Based on this theory, the abnormal growth conditions of a specific grain can be expressed as a function of only three parameters: the size ratio, boundary energy ratio, and mobility ratio between the specific grain and its surrounding matrix grains. However, quantitative and systematic validation of this theory is not yet reported neither in experiments nor simulations. In this study, to elucidate the validity of the mean-field theory, we perform large-scale phase-field simulations for two-dimensional and three-dimensional abnormal grain growth. The multi-phase-field numerical model and parallel graphics processing unit computing are employed, which enables the accurate analyses of abnormal growth in large-scale systems with several hundreds of thousands of grains while accounting for the nonuniformity in grain boundary properties. Systematic simulations are performed while varying the size ratio, boundary energy ratio, and mobility ratio between the specific grain and matrix grains. The simulated results and theoretical predictions on the abnormal grain growth behaviors, i.e., whether or not the abnormal growth occurs and the maximum size that can be reached by an abnormally growing grain, are compared in detail. The large-scale multi-phase-field simulations reveal for the first time the agreement between the mean-field theory and numerical simulation quantitatively, demonstrating that the mean-field theory is a versatile means for describing abnormal grain growth. [GRAPHICS] .
2022年09月07日, 研究論文(学術雑誌), 共同, 57, 35, 0022-2461,
DOI(公開)(r-map), 16690, 16709
Bayesian texture optimization using deep neural network-based numerical material testRyunosuke Kamijyo, Akimitsu Ishii, Sam Coppieters, Akinori Yamanaka
International Journal of Mechanical Sciences
PERGAMON-ELSEVIER SCIENCE LTD
The formability of an aluminum alloy sheet can be improved by optimizing its crystallographic texture. Computational methods for texture optimization that combine crystal plasticity simulations with mathematical optimization algorithms are computationally inefficient. The crux of the problem is that conventional texture optimization strategies rely on multiple time-consuming crystal plasticity simulations. In this paper, we propose a new computational method for mitigating computational effort in numerical crystallographic texture optimization. The key point of the proposed method is that it achieves a significant speed-up factor of approximately three-fold. First, we propose a deep neural network-based approach for the computationally efficient estimation of mechanical properties based on the crystallographic texture. Second, we adopted Bayesian optimization to deal with a small number of trials robustly and efficiently. It is shown that the proposed computational method, christened Bayesian texture optimization, enables the determination of optimal volume fractions of preferred texture components to obtain a plastically isotropic aluminum alloy sheet. Moreover, unlike conventional methods, Bayesian texture optimization provides a framework that enables a profound understanding of the solution space that may consist of other desirable textures and associated uncertainties. Bayesian texture optimization paves the way for useful engineering tools that can improve the mechanical properties and formability of aluminum alloy sheets.
2022年06月01日, 研究論文(学術雑誌), 共同, 223, 0020-7403,
DOI(公開)(r-map), 107285
BOXVIA: Bayesian optimization executable and visualizable applicationAkimitsu Ishii, Ryunosuke Kamijyo, Akinori Yamanaka, and Akiyasu Yamamoto
SoftwareX
Elsevier
Bayesian optimization (BO) has attracted attention in various research fields as a powerful probabilistic approach for solving optimization problems. To further facilitate the use of BO, we developed a graphical user interface-based Python application called BOXVIA. BOXVIA enables the use of BO without the construction of a computing environment and/or the need for programming skills. Moreover, BOXVIA helps users interpret the results of the BO process effectively through certain useful functionalities available for visualizing the mean function, standard deviation, and acquisition functions. (C) 2022 The Author(s). Published by Elsevier B.V.
2022年06月, 研究論文(学術雑誌), 共同, 18, 2352-7110,
DOI(公開)(r-map), 101019
Efficient estimation of material parameters using DMC-BO: Application to phase-field simulation of solid-state sinteringAkimitsu Ishii, Akinori Yamanaka, Eisuke Miyoshi and Akiyasu Yamamoto
Materials Today Communications
Elsevier
Phase-field (PF) simulations require data on physical properties and material parameters, which are largely unknown. Although data assimilation (DA) offers a way to estimate unknown material parameters and unobservable states through integration of simulation results and experimental data, conventional DA methods involve high computational costs and implementation difficulties. Therefore, in this study, we developed a new DA method: Data assimilation method Minimizing a four-dimensional Cost function using Bayesian optimization (DMC-BO). Using Bayesian optimization to minimize the data misfit between simulations and experiments leads to overcome the cost and implementation problems under conventional DA methods. To validate the accuracy and computational efficiency of the state and material parameter estimations obtained using DMC-BO, we applied the method to a PF model of highly nonlinear solid-state sintering, and we conducted numerical experiments called twin experiments. The twin experiments demonstrated that DMC-BO can yield highly accurate state estimation results and reasonably accurate material parameter estimation results, at less than half the computational cost of the conventional ensemble 4DVar DA method. Overall, the developed DMC-BO method is an advanced and powerful method whereby unobservable states and unknown material parameters can be obtained, which are essential for elucidating microstructural evolutions, with simplified PF model implementation and low computational costs.
2022年03月, 研究論文(学術雑誌), 共同, 30,
DOI(公開)(r-map), 103089
Image features of a splashing drop on a solid surface extracted using a feedforward neural networkJingzu Yee, Akinori Yamanaka, and Yoshiyuki Tagawa
Physics of Fluids
AIP Publishing
This article reports nonintuitive characteristic of a splashing drop on a solid surface discovered through extracting image features using a feedforward neural network (FNN). Ethanol of area-equivalent radius about 1.29 mm was dropped from impact heights ranging from 4 cm to 60 cm (splashing threshold 20 cm) and impacted on a hydrophilic surface. The images captured when half of the drop impacted the surface were labeled according to their outcome, splashing or nonsplashing, and were used to train an FNN. A classification accuracy & GE; 96 % was achieved. To extract the image features identified by the FNN for classification, the weight matrix of the trained FNN for identifying splashing drops was visualized. Remarkably, the visualization showed that the trained FNN identified the contour height of the main body of the impacting drop as an important characteristic differentiating between splashing and nonsplashing drops, which has not been reported in previous studies. This feature was found throughout the impact, even when one and three-quarters of the drop impacted the surface. To confirm the importance of this image feature, the FNN was retrained to classify using only the main body without checking for the presence of ejected secondary droplets. The accuracy was still & GE; 82 %, confirming that the contour height is an important feature distinguishing splashing from nonsplashing drops. Several aspects of drop impact are analyzed and discussed with the aim of identifying the possible mechanism underlying the difference in contour height between splashing and nonsplashing drops. (C) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
2022年01月20日, 研究論文(学術雑誌), 共同, 34, 1, 1070-6631,
DOI(公開)(r-map), 013317
データ科学を駆使した金属材料の組織形成と塑性変形予測山中晃徳
ぷらすとす
2021年12月25日, (MISC)総説・解説(学術雑誌), 単独, 48,
DOI(公開)(r-map), 809, 813
Novel estimation method for anisotropic grain boundary properties based on Bayesian data assimilation and phase-field simulationMiyoshi, Eisuke; Ohno, Munekazu; Shibuta, Yasushi; Yamanaka, Akinori; Takaki, Tomohiro
MATERIALS & DESIGN
ELSEVIER SCI LTD
Utilizing the data assimilation and multi-phase-field grain growth model, this study proposes a novel framework of measuring anisotropic (nonuniform) grain boundary energy and mobility. The framework can evaluate a large number of boundary properties from typical observations of grain growth without requiring specifically designed experiments or calculations. In this method, by optimizing the multiphase-field model parameters such that the simulation results are in good agreement with the observation data, the energies and mobilities of multiple individual boundaries are directly and simultaneously estimated. To validate the method, numerical tests on boundary property estimation were performed using synthetic microstructure dataset generated from grain growth simulations with a priori assumed property values. Systematic tests on simple tricrystal systems confirmed that the proposed method accurately estimates each boundary energy and mobility within an error of only several % of their assumed true values even for conditions with strong property anisotropy and grain rotation. Further numerical tests were conducted on a more general multi-grain system, showing that our method can be successfully applied to complicated polycrystalline grain growth. The obtained results demonstrate the potential of the proposed method in extracting a large dataset of grain boundary properties for arbitrary boundaries from actual grain growth observations. (C) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
2021年11月15日, 研究論文(学術雑誌), 共同, 210, 0264-1275,
DOI(公開)(r-map), 110089
Estimation of solid-state sintering and material parameters using phase-field modeling and ensemble four-dimensional variational methodIshii, Akimitsu; Yamanaka, Akinori; Miyoshi, Eisuke; Okada, Yuki; Yamamoto, Akiyasu
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
IOP PUBLISHING LTD
Sintering is a fundamental technology for powder metallurgy, the ceramics industry, and additive manufacturing processes such as three-dimensional printing. Improvement of the properties of sintered materials requires prediction of their microstructure using numerical simulations. However, the physical values and material parameters used for such predictions are generally unknown. Data assimilation (DA) enables the estimation of unobserved states and unknown material parameters by integrating simulation results and observational data. In this paper, we develop a new model that couples an ensemble-based four-dimensional variational (En4DVar) DA with a phase-field model of solid-state sintering (En4DVar-PF model) to estimate the state of the sintered material and multiple unknown material parameters. The developed En4DVar-PF model is validated by numerical experiments called twin experiments, in which a priori assumed-true initial state and multiple material parameters are estimated. The results of the twin experiments demonstrate that, using only three-dimensional morphological data of the sintered microstructure, our developed En4DVar-PF model can simultaneously and accurately estimate the particle shape, distribution of grain boundaries, and material parameters, including diffusion coefficients and mobilities related to grain boundary migration. Furthermore, our work identifies criteria for determining appropriate DA conditions such as the observational time interval required to accurately estimate the material parameters using our developed model. The developed En4DVar-PF model provides a promising framework to obtain unobservable states and difficult-to-measure material parameters in sintering, which is crucial for the accurate prediction of sintering processes and for the development of superior materials.
2021年09月, 研究論文(学術雑誌), 共同, 29, 6, 0965-0393,
DOI(公開)(r-map), 65012
Quantitative three-dimensional phase-field modeling of dendritic solidification coupled with local ensemble transform Kalman filterTakahashi, Kazuki; Yamanaka, Akinori
COMPUTATIONAL MATERIALS SCIENCE
ELSEVIER
Prediction of dendrite growth during alloy solidification is important for controlling the microstructures and mechanical properties of alloys. To this end, quantitative phase-field (QPF) models have been developed to accurately predict dendrite growth. However, a comprehensive method to calibrate the parameters of the QPF models has not been established. In this study, QPF modeling of dendritic solidification coupled with a data assimilation method based on the local ensemble transform Kalman filter (LETKF) is proposed. This modeling could simultaneously estimate multiple parameters and improve the prediction of dendrite growth. The modeling was applied to simulations of isothermal dendritic solidification in Fe-C-Mn ternary alloys. The results show that the solid-liquid interfacial energy and diffusion coefficients of solute atoms in a liquid phase can be estimated from the shapes of the growing dendrites. The accuracy of parameter estimation depends on the growth rate of the primary dendrite arm instead of the dendrite shape. This study demonstrates that LETKF-based data assimilation improves the prediction of solute concentration fields. The proposed QPF modeling paves a promising way to improve the prediction accuracy of conventional QPF models and derive new knowledge from the experimental data obtained by in-situ observations of growing dendrites.
2021年04月01日, 研究論文(学術雑誌), 共同, 190, 0927-0256,
DOI(公開)(r-map), 110296
Development of Microstructure Simulation System in SIP-Materials Integration ProjectsKoyama, Toshiyuki; Ohno, Munekazu; Yamanaka, Akinori; Kasuya, Tadashi; Tsukamoto, Susumu
MATERIALS TRANSACTIONS
JAPAN INST METALS & MATERIALS
A simulation system for the phase transformations and microstructure changes in welded area of steels was built with Materials Integration (MI) concepts. We aimed to build an simulation environment suitable not only for conducting research on microstructure developments and performing high-quality simulations but also for integrating practical and academic viewpoints and insights from materials science and engineering. In particular, the methods discussed in this article, such as the coordination of CCT diagrams and phase field (PF) simulations, and combination between PF methods and cellular automaton method, are typical examples of the MI concept. The detail of framework on the simulation system is explained, comprehensively.
2020年12月, 研究論文(学術雑誌), 共同, 61, 11, 1345-9678,
DOI(公開)(r-map), 2047, 2051
Data assimilation for three-dimensional phase-field simulation of dendritic solidification using the local ensemble transform Kalman filterYamanaka, Akinori; Takahashi, Kazuki
MATERIALS TODAY COMMUNICATIONS
ELSEVIER
Data assimilation (DA) based on Bayes' theorem helps improve the accuracy of numerical models and simultaneously enables the estimation of unknown parameters used in the numerical model by combining simulation results with observational data. We applied the local ensemble transform Kalman filter (LETKF), a computationally efficient and accurate DA methodology, to a phase-field model of dendritic solidification in a binary alloy. We demonstrated the efficiency of LETKF through numerical experiments (twin experiments) wherein we estimated the unknown state of the solidification and the model parameters from synthetic observation datasets of a growing dendrite morphology. Results of the twin experiments show that using LETKF we could successfully estimate three-dimensional (3D) time evolution of the solute concentration-field in the liquid phase. Further, we could inversely identify multiple model parameters, including interfacial energy between the solid and liquid phases and the solute diffusion coefficient in the liquid phase only from the 3D morphological information of a growing dendrite. We demonstrated that the LETKF-based DA method is a promising methodology for performing accurate phase-field simulations in conjunction with experimental data.
2020年12月, 研究論文(学術雑誌), 共同, 25, 2352-4928,
DOI(公開)(r-map), 101331
Estimation of Texture-Dependent Stress-Strain Curve and r-Value of Aluminum Alloy Sheet Using Deep LearningKoenuma, Kohta; Yamanaka, Akinori; Watanabe, Ikumu; Kuwabara, Toshihiko
MATERIALS TRANSACTIONS
JAPAN INST METALS & MATERIALS
The deformation of an aluminum alloy sheet is affected by its underlying crystallographic texture and has been extensively studied using the crystal plasticity finite element method (CPFEM). Numerical material test based on the CPFEM enables the quantitative estimation of the stress-strain curve and Lankford value (r-value), which depend upon the texture of aluminum alloy sheets. However, the application of CPFEM-based numerical material test to the optimization of aluminum alloy texture is computationally expensive. In this paper, we propose a method for rapidly estimating the stress-strain curves and r-values of aluminum alloy sheets using deep learning with a neural network. We train the neural network with the synthetic crystallographic texture and stress-strain curves calculated through the numerical material tests. To capture the features of synthetic texture from a {111} pole-figure image, the neural network incorporates a convolution neural network. Using the trained neural network, we estimate the uniaxial stress-strain curve and in-plane anisotropy of the r-value for various textures that contain Cube and S components. The results indicate that the application of a neural network trained with the results of numerical material test is a promising method for rapidly estimating the deformation of aluminum alloy sheets.
2020年11月, 研究論文(学術雑誌), 共同, 61, 12, 1345-9678,
DOI(公開)(r-map), 2276, 2283
Multi-phase-field modelling of electromigration-induced void migration in interconnect lines having bamboo structuresIshii, Akimitsu; Yamanaka, Akinori
COMPUTATIONAL MATERIALS SCIENCE
ELSEVIER
Predicting the evolution of voids induced by electromigration (EM) in interconnect lines is an important aspect of improving the reliability of miniaturized integrated circuits. In this paper, we propose a new multi-phase-field (MPF) model to simulate void evolution in polycrystalline interconnect lines on a three-dimensional (3D) basis. This model was validated by comparing simulations of 3D void migration in a single crystal copper line with analytical solutions. We also performed a parametric study intended to elucidate the key factors associated with void evolution leading to line breakage. This study determined that critical void evolution in copper straight interconnect lines having a bamboo structure depends on the ratio of the diffusion coefficient of atoms at the grain boundaries to that at the void surfaces. Simulations in which multiple voids migrated by EM in a bamboo line mimicking a via site in an integrated circuit showed that such voids tend to accumulate and break the interconnect line above the via. By comparing simulation results to experimental data, this work also confirmed that the MPF model can predict the break point of an interconnect line as caused by EM.
2020年11月, 研究論文(学術雑誌), 共同, 184, 0927-0256,
DOI(公開)(r-map), 109848
Deep neural network approach to estimate biaxial stress-strain curves of sheet metalsYamanaka, Akinori; Kamijyo, Ryunosuke; Koenuma, Kohta; Watanabe, Ikumu; Kuwabara, Toshihiko
MATERIALS & DESIGN
ELSEVIER SCI LTD
To improve the accuracy of a sheet metal forming simulation, the constitutive model is calibrated using results from multiaxial material testing. However, multiaxial material testing is time-consuming and requires specialized equipment. This study proposes two different deep neural network (DNN) approaches, a twoand threedimensional convolutional neural network (DNN-2D and DNN-3D), to efficiently estimate biaxial stress-strain curves of aluminum alloy sheets from a digital image representing the sample's crystallographic texture. DNN2D is designed to estimate biaxial stress-strain curves from a digital image of {111} pole figure, while DNN-3D estimates the curves from a 3D image of the texture. The two DNNs were trained using synthetic texture datasets and the corresponding biaxial stress-strain curves obtained from crystal plasticity-based numerical biaxial tensile tests. The accuracy of the two trained DNNs was examined by comparing the results from that of the numerical biaxial tensile tests. It was observed that both the DNNs could estimate biaxial stress-strain curves with high accuracy. Though DNN-3D provides with a better estimation than DNN-2D, it displays lower computational efficiency. Thus, the two DNNs and their training procedures offer a new and efficient method to provide virtual data for material modeling. (c) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
2020年10月, 研究論文(学術雑誌), 共同, 195, 0264-1275,
DOI(公開)(r-map), 108970
Grain boundary mobilities in polycrystalsZhang, Jin; Ludwig, Wolfgang; Zhang, Yubin; Sorensen, Hans Henrik B.; Rowenhorst, David J.; Yamanaka, Akinori; Voorhees, Peter W.; Poulsen, Henning F.
ACTA MATERIALIA
PERGAMON-ELSEVIER SCIENCE LTD
Most metals, ceramics, semiconductors and rocks are composed of small crystals known as grains. When annealed, this polycrystalline structure coarsens, thus allowing the properties of a material to be tailored for a particular application. The mobility of grain boundaries is thought to be determined by the crystallography of the adjacent crystals, but experimental validation in bulk polycrystalline materials is lacking. Here we developed a novel fitting methodology by direct comparison of a time-resolved three-dimensional experimental data to simulations of the evolution of 1501 grains in iron. The comparison allows reduced mobilities of 1619 grain boundaries to be determined simultaneously. We find that the reduced mobilities vary by three orders of magnitude and in general exhibit no correlation with the boundary's five macroscopic degrees of freedom, implying that grain growth is governed by other factors. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd.
2020年06月01日, 研究論文(学術雑誌), 共同, 191, 1, 1359-6454,
DOI(公開)(r-map), 211, 220
深層学習を用いたアルミニウム合金板の集合組織に依存した応力-ひずみ曲線とr値の推定肥沼康太, 山中晃徳, 渡邊育夢, 桑原利彦
塑性と加工
日本塑性加工学会
2020年02月25日, 研究論文(学術雑誌), 共同, 61, 709,
DOI(公開)(r-map), 48, 55
Solidification analysis by non-equilibrium phase field model using thermodynamics data estimated by machine learningNomoto, Sukeharu; Wakameda, Hiroshi; Segawa, Masahito; Yamanaka, Akinori; Koyama, Toshiyuki
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
IOP PUBLISHING LTD
A multi-phase field method (MPFM) using the finite interface dissipation model is applied to simulate the solidification microstructure evolution of a stainless-steel composition, including the delta-ferrite to gamma austenite peritectic transformation. The calculation is performed for a quinary system of engineering steel in a two-dimensional field. Thermodynamics calculations using the CALPHAD database in this MPFM are replaced by machine learning prediction to reduce the numerical time. Neural network methodology is introduced for machine learning in this study. The Gibbs free energy and chemical potential values estimated from the CALPHAD database coupling results are inputted into the neural network learning procedure, together with the composition and temperature values. The microstructure evaluated using the obtained neural network parameter is in good agreement with that directly coupled with the CALPHAD database. This calculation is approximately five times faster than direct CALPHAD calculation.
2019年12月, 研究論文(学術雑誌), 共同, 27, 8, 0965-0393,
DOI(公開)(r-map), 84008
Ensemble Kalman filter-based data assimilation for three-dimensional multi-phase-field model: Estimation of anisotropic grain boundary propertiesYamanaka, Akinori; Maeda, Yuri; Sasaki, Kengo
MATERIALS & DESIGN
ELSEVIER SCI LTD
Data assimilation (DA) has been used as a machine learning approach to estimate a system's state and the unknown parameters in its numerical model by integrating observed data into model predictions. In this paper, we propose using the DA methodology based on the ensemble Kalman filter (EnKF) to improve the accuracy of microstructure prediction using three-dimensional multi-phase-field (3D-MPF) model and estimate the model parameters simultaneously. To demonstrate the applicability of the DA methodology, we performed numerical experiments in which a priori assumed true parameters related to the grain boundary (GB) energy cusp and GB mobility peak of Sigma 7 coincidence site lattice GB were estimated from synthetic data of timeevolving polycrystalline microstructure. Fourmodel parameters related to the Sigma 7 GB properties were successfully estimated by assimilating the synthetic microstructure data to the 3D-MPF model predictions using the EnKF-based DA method. Furthermore, we accurately reproduced the preliminarily assumed true shapes of GB energy cusp and GB mobility peak by using the estimated parameters. The results suggest that implementation of the EnKF-based DA method in the MPF model has great potential for identifying unknown material properties and estimating unmeasurable microstructure evolutions in polycrystalline materials based on real time-series 3D microstructure observation data. (C) 2018 Published by Elsevier Ltd.
2019年03月05日, 研究論文(学術雑誌), 共同, 165, 0264-1275,
DOI(公開)(r-map), 107577
Voxel coarsening approach on image-based finite element modeling of representative volume elementWatanabe, Ikumu; Yamanaka, Akinori
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
PERGAMON-ELSEVIER SCIENCE LTD
This study proposed an approach to reduce the high computational demand in image-based finite element modeling based on structured meshing. This approach generates a coarsened finite element mesh containing the two-level resolution of subunits and finer discretization around the phase-boundary through direct translation from an original voxel data of a microstructure. The proposed approach was applied to representative volume elements (RVEs) of polycrystalline aggregates, which are computational results of the recrystallization simulations with the multi-phase-field method. The deformation simulations of the RVEs were performed to evaluate the efficiency of the proposed approach. This approach enables us to reduce the number of elements by over 80% and easily set up the periodic boundary condition at nodes on the corresponding surfaces of the finite element model because the structured mesh in subunit resolution is maintained after the coarsening process.
2019年01月, 研究論文(学術雑誌), 共同, 150, 0020-7403,
DOI(公開)(r-map), 314, 321
Prediction of Static Recrystallization Nucleation Sites in Tensile Deformed Single Crystal Pure Iron through a Combination of In-Situ EBSD and CP-FEMLuo, Zichao; Yoshino, Masahiko; Terano, Motoki; Yamanaka, Akinori
METALS
MDPI
Microstructure control is of vital importance in tailoring physical properties of metallic materials. Despite the enormous efforts devoted to the study of microstructure evolution during recrystallization, most previous research has been conducted under non-simple conditions, either applying complex deforming boundary conditions or employing specimens with sophisticated crystalline structure. These complexities hinder comprehensive understanding of the fundamental aspects in texture evolution and make it even harder to penetrate the already intricate recrystallization behaviors. The present study aims at a detailed evaluation of widely used phenomenological model in reproducing experimentally observed deformation characteristics under simple crystalline structure and deformation condition, as well as the prediction of nucleation sites during static recrystallization. In situ electron back-scattering diffusion (EBSD) observations were performed to record texture change during static recrystallization of single crystal pure iron specimens after tensile deformation. CP-FEM (crystal plasticity finite element method) method was employed to simulate deformed texture. Deformation heterogeneity characterized by kernel average misorientation maps derived from EBSD data and numerical calculations were compared. The former data shows deformation heterogeneity sensitive to localized microstrain while the later delivers an effective meso-scale deformation distribution. Observed approximate nucleation sites have shown a qualitative coincidence with highly distorted regions in numerical calculations.
2018年10月, 研究論文(学術雑誌), 共同, 8, 10, 2075-4701,
DOI(公開)(r-map) Phase-Field Simulation of alpha Growth Stagnation During gamma -> alpha Transformation in Fe-X-Y and Fe-C-Mn AlloysKohtake, Takahiko; Yamanaka, Akinori; Suwa, Yoshihiro
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
SPRINGER
In multicomponent steels such as Fe-C-Mn alloys that contain substitutional alloying elements, the stagnation of ferrite (alpha) growth during the austenite-to-ferrite (gamma -> alpha) transformation has been experimentally observed under specific chemical compositions and temperatures. The purpose of this study is to investigate the alpha growth stagnation by the phase-field (PF) method. We examined the effect of the diffusivity of the substitutional alloying element on the stagnation by simulating the isothermal gamma -> alpha transformation in virtual Fe-X-Y and real Fe-C-Mn alloys. The results for the Fe-X-Y alloy showed that at a specific diffusivity of the substitutional Y element, the alpha growth stagnated without the soft impingement of the interstitial X atoms. This applied for alloys with initial compositions in the partitioning local equilibrium (PLE) and para-equilibrium (PE) regions of the phase diagram. The stagnation was demonstrated to be caused by the alpha growth mode transition from the PE to PLE mode, which was triggered by the formation of the substitutional solute spike at the alpha/gamma interface. The results for the Fe-C-Mn alloy verified that the alpha growth mode transition also caused the stagnation of a growth in the multi-component steels. (C) The Minerals, Metals & Materials Society and ASM International 2018
2018年10月, 研究論文(学術雑誌), 共同, 49A, 10, 1073-5623,
DOI(公開)(r-map), 5023, 5034
Prediction of static recrystallization nucleation sites in tensile deformed single crystal
pure iron through a combination of in-situ EBSD and CP-FEMZichao Luo, Masahiko Yoshino, Motoki Terano, and Akinori Yamanaka
Metals
MDPI
2018年10月, 研究論文(学術雑誌), 共同, 8, 10,
DOI(公開)(r-map), 858
Phase-field modeling for pHdependent general and pitting corrosion of ironTsuyuki, Chisa; Yamanaka, Akinori; Ogimoto, Yasushi
SCIENTIFIC REPORTS
NATURE PUBLISHING GROUP
This study proposes a new phase-field (PF) model to simulate the pH-dependent corrosion of iron. The model is formulated based on Bockris's iron dissolution mechanism to describe the pH dependence of the corrosion rate. We also propose a simulation methodology to incorporate the thermodynamic database of the electrolyte solutions into the PF model. We show the applications of the proposed PF model for simulating two corrosion problems: general corrosion and pitting corrosion in pure iron immersed in an acid solution. The simulation results of general corrosion demonstrate that the incorporation of the anodic and cathodic current densities calculated by a Corrosion Analyzer software allows the PF model to simulate the migration of the corroded iron surface, the variation of ion concentrations in the electrolyte, and the electrostatic potential at various pH levels and temperatures. The simulation of the pitting corrosion indicates that the proposed PF model successfully captures the anisotropic propagation of a pit that is affected by the local pH of the electrolyte solution and the aggregation of Cl-ions in the pit.
2018年08月24日, 研究論文(学術雑誌), 共同, 8, 2045-2322,
DOI(公開)(r-map) Phase-field modeling for pH-dependent general and pitting corrosion of ironChisa Tsuyuki, Akinori Yamanaka, Yasushi Ogimoto
Scientific Reports
Spinger Nature
2018年08月, 研究論文(学術雑誌), 共同, 8,
DOI(公開)(r-map), 12777
Phase-field simulation of ferrite growth stagnation during austenite-to-ferrite transformation in Fe-X-Y and Fe-C-Mn alloysTakahiko Kohtake, Akinori Yamanaka, Yoshihiro Suwa
Metallurgical and Materials Transactions A
Springer
2018年07月, 研究論文(学術雑誌), 共同, 49,
DOI(公開)(r-map), 5023-5034
Data assimilation for phase-field models based on the ensemble Kalman filterSasaki, Kengo; Yamanaka, Akinori; Ito, Shin-ichi; Nagao, Hiromichi
COMPUTATIONAL MATERIALS SCIENCE
ELSEVIER SCIENCE BV
We have developed a data assimilation (DA) methodology based on the ensemble Kalman filter (EnKF) for estimating unknown parameters involved in a phase-field model from observational/experimental data. The DA methodology based on Bayesian statistics is able to estimate parameters by incorporating observational/experimental data into the phase-field model and evaluate the uncertainty of the estimated parameters. In this paper, we apply the EnKF-based DA method to estimate the phase-field mobility for a phase-field simulation of the isothermal austenite-to-ferrite transformation in a Fe-C-Mn alloy. Our DA method is validated through numerical experiments called ”twin experiments” to verify that the DA method can estimate a priori assumed-true phase-field mobility from synthetic observational data. The results of the twin experiments using various initial phase-field mobilities show that our DA methodology can successfully estimate the true phase-field mobility, even when the initial value largely deviates from the true value. Furthermore, our DA method reveals the sampling interval for observational data necessary to accurately estimate the parameter and its uncertainty. (C) 2017 Elsevier B.V. All rights reserved.
2018年01月, 研究論文(学術雑誌), 共同, 141, 0927-0256,
DOI(公開)(r-map), 141, 152
Multi-phase-field simulation of cyclic phase transformation in Fe-C-Mn and Fe-C-Mn-Si alloysSegawa, Masahito; Yamanaka, Akinori; Nomoto, Sukeharu
COMPUTATIONAL MATERIALS SCIENCE
ELSEVIER SCIENCE BV
The stagnant and inverse transformation stages during cyclic phase transformation in the two-phase region ”ferrite + austenite” (intercritical region) of Fe-C-Mn and Fe-C-Mn-Si alloys were investigated using the non-equilibrium multi-phase-field (NEMPF) model, i.e. an MPF model with finite interface dissipation. We showed that if we used large interfacial permeability parameters that characterize the partitioning rate of solute atoms in the ferrite/austenite interface, the NEMPF model predicted the same transformation behavior as that simulated using the MPF model based on the assumption of the parallel tangent law. The simulation demonstrated that the inverse transformation stage, in which ferrite-to-austenite transformation proceeds despite decreasing temperature, could be naturally described by the NEMPF model coupled with the CALPHAD-based thermodynamic database. This study also elucidated a switching of the polarities of Mn and Si spike formed at the ferrite/austenite interface governed the driving force of the austenite-to-ferrite transformation and caused the stagnant stage where the phase transformation was suppressed. Furthermore, the impact of the amount of Mn and Si atoms on the stagnant stage length was examined using the NEMPF model. The simulations revealed that increasing the concentration of Mn and Si extended the stagnant stage, with a more pronounced effect with Mn rather than Si atoms. (C) 2017 Elsevier B.V. All rights reserved.
2017年08月, 研究論文(学術雑誌), 共同, 136, 0927-0256,
DOI(公開)(r-map), 67, 75
Phase field crystal simulation of grain boundary motion, grain rotation and dislocation reactions in a BCC bicrystalYamanaka, Akinori; McReynolds, Kevin; Voorhees, Peter W.
ACTA MATERIALIA
PERGAMON-ELSEVIER SCIENCE LTD
We investigate grain boundary motion and grain rotation in a body-centered cubic bicrystal composed of a spherical grain embedded in a single crystal matrix by three-dimensional phase-field crystal simulations. Structure and time evolution of dislocation networks formed on the grain boundary during the capillarity-driven grain shrinkage are examined. The results for initially spherical grains rotated about the 11101 or 11111 axes of the matrix grain reveal the formation of hexagonal dislocation networks (HDNs) on the grain boundary.,We demonstrate that the anisotropic distribution of the HDNs is responsible for asymmetric shrinkage of the embedded grain. Through a detailed analysis of the HDNs, we clarify the mechanisms of dislocation reactions during the grain shrinkage in three dimensions, which include dissociation and recombination of a/2 < 111 > and a < 100 > dislocations. The configuration of the HDNs is strongly affected by the rotation axis of the embedded grain. For large misorientations, the high density of the HDNs accelerates dislocation reactions and leads to very small grain rotations. However, if the misorientation is small and the dislocations are further apart, the lack of dislocation reactions on grain shrinkage results in grain rotation. Even though the rotation axis and the misorientation strongly affect the grain shape and the grain rotation, the kinetics of the grain shrinkage associated with the grain rotation follow the classical theory for grain growth: area of the embedded grain shrinks linearly with time. We also show that the stagnation of the grain rotation slows the shrinkage of the embedded grain. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
2017年07月, 研究論文(学術雑誌), 共同, 133, 1359-6454,
DOI(公開)(r-map), 160, 171
Analysis of gamma ->alpha transformation in Fe-C-Mn ternary alloy by phase-field simulation coupled with CALPHAD databaseKohtake, Takahiko; Segawa, Masahito; Yamanaka, Akinori
JOURNAL OF CRYSTAL GROWTH
ELSEVIER SCIENCE BV
We investigate the isothermal austenite-to-ferrite (gamma ->alpha) transformation behaviors in a Fe-C-Mn ternary alloy simulated by the phase-field (PF) models based on the Kim-Kim-Suzuki (KKS) model and the linearized phase diagram by comparing with that predicted by the analytical model of diffusional phase transformations: the Coates model. The growth rates of the a phase during the transformation calculated by one-and two-dimensional PF simulations coupled with the CALPHAD (CALculation of PHAse Diagram) database are compared with that obtained from the Coates model. The results show that the kinetics of the gamma ->alpha transformation in the Fe-0.55C-3.12Mn [at%] alloy simulated by both PF models are close to the paraequili-brium (PE) mode. The results also indicate that the growth behavior of the a phase transits from interface-controlled to diffusion-controlled growth as the mobility of the austenite/ferrite (gamma/alpha) interface increases. Furthermore, we clarify that the growth rate of the a phase calculated by the PF model based on the KKS model is found to be in good agreement with that calculated by the Coates model under the specific condition where the gamma ->alpha transformation proceeds without Mn diffusion, i.e., the PE mode, and the mobility of the gamma/alpha interface is high.
2017年06月, 研究論文(国際会議プロシーディングス), 共同, 468, 0022-0248,
DOI(公開)(r-map), 63, 67
Analysis of γ→α Transformation in Fe-C-Mn Ternary Alloy by Multiphase-field Simulation Coupled with CALPHAD DatabaseTakahiko Kohtake, Masahito Segawa, Akinori Yamanaka
Journal of Crystal Growth
2017年06月, 研究論文(学術雑誌), 共同, 468,
DOI(公開)(r-map), 63, 57
Microstructure-based Multiscale Analysis of Hot Rolling of Duplex Stainless Steel Using Various Simulation Software
Sukeharu Nomoto, Mototeru Oba, Kazuki Mori, Akinori Yamanaka
Integrating Materials and Manufacturing Innovation
2017年03月, 研究論文(学術雑誌), 共同, 6, 69, 82
Numerical Biaxial Tensile Test of Aluminum Alloy Sheets using Crystal Plasticity Model Implemented in Commercial FEM software
Shohei Ochiai, Akinori Yamanaka, Toshihiko Kuwabara
Key Engineering Materials
2016年12月, 研究論文(学術雑誌), 共同, 725, 255, 260
Data assimilation for massive autonomous systems based on second-order adjoint method
Shin-ichi Ito, Hiromichi Nagao, Akinori Yamanaka, Yuhki Tsukada, Toshiyuki Koyama, Masayuki Kano and Junya Inoue
Physical Review E
2016年10月, 研究論文(学術雑誌), 共同, 94, 043307
Numerical biaxial tensile test for sheet metal forming simulation of aluminum alloy sheets based on the homogenized crystal plasticity finite element method
Akinori Yamanaka, Yoshiaki Ishii, Tomoyuki Hakoyama, Philip Eyckens, Toshihiko Kuwabara
Journal of Physics: Conference Series
2016年09月, 研究論文(学術雑誌), 共同, 734, 032005
金属板材成形のマルチスケールモデリング -フェーズフィールドモデルと結晶塑性モデルの応用-
山中晃徳
塑性と加工
2016年03月, 単独, 67, 662, 209, 214
結晶塑性解析とマルチフェーズフィールド法を用いた軽金属材料の変形および再結晶組織予測
山中晃徳
軽金属
2015年11月, 単独, 65, 11, 542, 548
均質化結晶塑性有限要素法に基づく数値二軸引張試験を用いたアルミニウム合金板の材料モデリングおよび成形シミュレーション
山中晃徳, 橋本圭右, 川口順平, 櫻井健夫, 桑原利彦
軽金属
2015年11月, 研究論文(学術雑誌), 共同, 65, 11, 561, 567
Control of γ lamella precipitation in Ti-39 at.% Al single crystals by nanogroove-induced dislocation bands
Dai-Xiu Wei, Yuichiro Koizumi, Akinori Yamanaka, Masahiko Yoshino, Yungping Li, Akihiko Chiba
Acta Materialia
2015年09月, 研究論文(学術雑誌), 共同, 96, 352, 365
Prediction of 3D Microstructure and Plastic Deformation Behavior in Dual-Phase Steel Using Multi-Phase Field and Crystal Plasticity FFT Methods
Akinori Yamanaka
Key Engineering Materials
2015年07月, 研究論文(学術雑誌), 単独, 651-653, 570, 574
均質化法に基づく結晶塑性有限要素法による5000系アルミニウム合金板の二軸引張変形解析と実験検証
橋本圭右, 山中晃徳, 川口順平, 櫻井健夫, 桑原利彦
軽金属
2015年06月, 研究論文(学術雑誌), 共同, 65, 5, 196, 203
Multi-Phase-Field Simulation of Flow Stress and Microstructural
Evolution during Deformation-induced Ferrite Transformation in a Fe-C AlloyAkinori Yamanaka and Tomohiro Takaki
ISIJ International
2014年12月, 研究論文(学術雑誌), 共同, 54, 12,
DOI(公開)(r-map), 2917, 2925
マルチフェーズフィールド法を用いた鉄鋼材料の組織形成と変形挙動の数値シミュレーション
山中晃徳, 高木知弘額
ふぇらむ
2014年11月, 共同, 19, 765, 774
超微細塑性加工と焼鈍法の組合せにより作製した金属ナノドットアレイの光学特性吉野雅彦, 永松明浩, 李振星, 山中晃徳, 山本貴富貴
日本機械学会論文集
2014年09月, 研究論文(学術雑誌), 共同, 80, 817,
DOI(公開)(r-map), MN0272
Nanoplastic Deformation on Ti-39 at.% Al Single Crystals for Manipulation of Every Single Gamma LamellaWei Daixiu, Yuichiro Koizumi, Hiroaki Nishiyama, Akinori Yamanaka, Masahiko Yoshino, Shinpei Miyamoto, Kyosuke Yoshimi and Akihiko Chiba
Acta Materialia
2014年09月, 研究論文(学術雑誌), 共同, 76,
DOI(公開)(r-map), 331, 341
Multi-Phase-Field Analysis of Stress-Strain Curve and Ferrite Grain Formation during Dynamic Strain-induced Ferrite Transformation
Akinori Yamanaka and Tomohiro Takaki
Key Engineering Materials
2014年08月, 研究論文(学術雑誌), 単独, 626, 81, 84
Regularly-formed Three-dimensional Gold Nanodot Array with Controllable Optical PropertiesLi Zhenxing, Masahiko Yoshino and Akinori Yamanaka
Journal of Micromechanics and Microengineering
2014年04月, 研究論文(学術雑誌), 共同, 24,
DOI(公開)(r-map), 045011
Multiscale Modeling of Hot-working with Dynamic Recrystallization by Coupling Microstructure Evolution and Macroscopic Mechanical BehaviorTomohiro Takaki, Chihiro Yoshimoto, Akinori Yamanaka and Yoshihiro Tomita
International Journal of Plasticity
2014年01月, 研究論文(学術雑誌), 共同, 52,
DOI(公開)(r-map), 105, 116
Effects of Morphology of Nanodots on Localized Surface Plasmon Resonance Property
Truong Duc Phuc, Masahiko Yoshino, Akinori Yamanaka and Takatoki Yamamoto
International Journal of Automation Technology
2013年12月, 研究論文(学術雑誌), 共同, 8, 74, 82
マルチフェーズフィールド法による多結晶粒成長シミュレーションの複数GPU計算岡本成史、山中晃徳、下川辺隆史、青木尊之
日本計算工学会論文集
2013年11月, 研究論文(学術雑誌), 共同, 2013,
DOI(公開)(r-map), 20130018
Multiscale Modeling of Hot-working with Dynamic Recrystallization by Coupling Microstructure Evolution and Macroscopic Mechanical BehaviorTomohiro Takaki, C. Yoshimoto, Akinori Yamanaka and Yoshihiro Tomita
International Journal of Plasticity
2013年09月, 研究論文(学術雑誌), 共同, 52,
DOI(公開)(r-map), 105, 116
Unexpected Selection of Growing Dendrites by Very-Large-Scale Phase-Field SimulationTomohiro Takaki, Takashi Shimokawabe, Munekazu Ohno,
Akinori Yamanaka and Takayuki Aoki.
Journal of Crystal Growth
2013年08月, 研究論文(学術雑誌), 共同, 382, 1,
DOI(公開)(r-map), 21, 25
Optical Properties of Multilayer Ordered Gold Nanodot Array Fabricated by a Thermal Dewetting MethodZhenxing Li, Masahiko Yoshino and Akinori Yamanaka
Procedia CIRP
2013年03月, 研究論文(学術雑誌), 共同, 5,
DOI(公開)(r-map), 42, 46
Fabrication of gold nanodot array on plastic films for bio-sensing applicationsThuong Duc Phuc, Masahiko Yoshino, Akinori Yamanaka, Takatoki Yamamoto
Procedia CIRP
2013年03月, 研究論文(学術雑誌), 共同, 5,
DOI(公開)(r-map), 47, 52
Simulation of Microstructure Evolution and Deformation Behavior for Dual-phase Steel by Multi-phase-field Method and Elastoplastic Finite Element Method
Akinori Yamanaka and Tomohiro Takaki
International Journal of Automation Technology
2012年11月, 研究論文(学術雑誌), 共同, 7, 16, 23
データ同化の基礎理論および演習
特定非営利活動法人 第43期非線形CAE協会勉強会
2023年12月16日, 公開講演,セミナー,チュートリアル,講習,講義等
数値シミュレーションと実験をつなぐデータ同化
一般社団法人 日本熱処理技術協会 2023年度 第2回熱処理技術セミナー
2023年10月24日, 口頭発表(招待・特別)
CAEに役立つデータ同化の基礎
特定非営利活動法人 第42期非線形CAE協会勉強会
2023年06月25日, 公開講演,セミナー,チュートリアル,講習,講義等
構造金属材料の変形・加工・破壊モデリングとデータ同化
名古屋大学 グリーン構造材料インフォマティクス研究部門 GiSM第4回ワークショップ
2023年03月29日, 口頭発表(招待・特別)
データ同化を用いたアルミニウム合金の加工・破壊のデジタルツイン構築
一般社団法人 軽金属溶接協会 年次講演大会
2023年01月31日, 口頭発表(招待・特別)
フェーズフィールドモデリングおよび有限要素解析へのデータ科学的手法の応用
日本鉄鋼協会 第155回 圧延理論部会
2022年12月01日, 口頭発表(招待・特別)
Applications of GPUs to Phase Field Simulations
& Perspectives on PFHub Benchmarks
CHiMaD Phase Field Methods XIV
2022年10月26日, 口頭発表(招待・特別)
Bayesian data assimilation for phase-field simulation of microstructure evolution
The 10th International Congress on Multiscale Materials modeling (MMM10)
2022年06月06日, 口頭発表(基調)
材料組織シミュレーション・データ同化の最前線
名古屋大学GiSM設立記念プレシンポジウム
2022年01月21日, 口頭発表(招待・特別)
Estimation of biaxial stress-strain curves for aluminum alloy sheets using deep neural network
25th International Congress of Theoretical and Applied Mechanics (ICTAM2020+1)
2021年08月26日, 口頭発表(一般)
畳み込みニューラルネットワークを用いたアルミニウム合金板材の二軸引張変形挙動の推定
日本塑性加工学会 2021年度塑性加工春季講演会
2021年06月03日, 口頭発表(一般)
単結晶純鉄の変形挙動に対する結晶方位の影響
日本塑性加工学会 2021年度塑性加工春季講演会
2021年06月03日, 口頭発表(一般)
Phase-Field法を用いたFe-C合金のフェライト変態における変態ひずみに起因した応力場解析
日本計算工学会 第26回計算工学講演会
2021年05月, 口頭発表(一般)
結晶塑性解析と深層学習を用いたアルミニウム合金板の変形挙動推定
日本塑性加工学会東京・南関東支部総会 第19回技術フォーラム「AI/IoTの塑性加工への適用」
2021年04月14日, 口頭発表(招待・特別)
Bayesian Data Assimilation for Phase-field simulation of Solid-state Sintering
TMS Annual Meeting & Exhibition 2021
2021年03月15日, 口頭発表(一般)
データ同化によるフェーズフィールドモデリングの進展と期待
PCoMS-SMee Multiscale Theory seminar, 東北大学計算物質科学人材育成コンソーシアム(PCoMS)
2021年01月19日, 口頭発表(招待・特別)
Phase-field simulation of solid-state sintering for predicting microstructural evolution in polycrystalline bulk superconducting material
14th World Congress in Computational Mechanics (WCCM)
2021年01月11日, 口頭発表(一般)
Estimation of biaxial tensile deformation behavior of aluminum alloy sheet using deep learning
14th World Congress in Computational Mechanics (WCCM)
2021年01月11日, 口頭発表(一般)
深層学習を用いたアルミニウム合金板の変形挙動推定
第2回高精度CAEのための実験技術およびデータ同化に関する研究会
2020年12月11日, 口頭発表(一般)
データ同化手法による流動応力・摩擦パラメータの推定
日本塑性加工学会 第71回塑性加工連合講演会
2020年11月14日, 口頭発表(一般)
Bayesian engineered high critical current density in K doped Ba122 polycrystalline materials
The 2020 Applied Superconductivity Conference (ASC2020)
2020年10月24日, 口頭発表(一般)
Influence of synthesis condition on grain-structure of Ba-122 polycrystalline bulks
The 2020 Applied Superconductivity Conference (ASC2020)
2020年10月24日, 口頭発表(一般)
Phase-Field Simulation of Stress Corrosion Cracking in Stainless Steel
Pacific Rim Meeting on Electrochemical And Solid-state Science 2020 (PRiME2020)
2020年10月04日, ポスター発表
Phase-field simulation of Li-ion diffusion and stress evolution in cathode materials in NCA-type-Li-ion batteries
Pacific Rim Meeting on Electrochemical And Solid-state Science 2020 (PRiME2020)
2020年10月04日, ポスター発表
Phase-field modelling and Bayesian data assimilation in materials science
The 6th Symposium on Theoretical and Applied Mechanics
2020年09月01日, 口頭発表(招待・特別)
多結晶型超伝導材料の微細組織形成予測のための固相焼結フェーズフィールドシミュレーション
日本計算工学会 第25回計算工学講演会
2020年06月10日, 口頭発表(一般)
磁区構造に及ぼす自由表面の効果のフェーズフィールド解析
第67回応用物理学会春季学術講演会
2020年03月12日, 口頭発表(一般)
材料分野へのデータ同化・機械学習の適用とその課題
一般社団法人 日本機械学会 計算力学部門 設計に活かすデータ同化研究会
2020年01月27日, 口頭発表(招待・特別)
Multi-phase-field simulation of cyclic phase transformation using neural network in Fe-C-Mn-Si alloy
Asian Pacific Congress on Computatioanl Mechanics (APCOM2019)
2019年12月18日, 口頭発表(一般)
Large-scale phase-field simulation of solid-state sintering in polycrystalline superconducting material using parallel computing
Asian Pacific Congress on Computatioanl Mechanics (APCOM2019)
2019年12月18日, 口頭発表(一般)
Data Assimilation for Three-dimensional Phase-field Simulation of Binary Alloy Solidification
Asian Pacific Congress on Computatioanl Mechanics (APCOM2019)
2019年12月18日, 口頭発表(一般)
Bayesian Data Assimilation Solver for Phase-field Models with Python
Asian Pacific Congress on Computatioanl Mechanics (APCOM2019)
2019年12月18日, 口頭発表(一般)
Material Parameter Estimation for Phase-field Simulation of Solid-state Sintering using Data Assimilation
Materials Research Meeting 2019 (MRM2019)
2019年12月10日, 口頭発表(一般)
A comparative study of experiments and simulations on grain-boundary formation of polycrystalline Ba122 phase iron-based superconductors
2019 MRS Fall Meeting
2019年12月, 口頭発表(一般)
Towards rapid throughout measurement of grain boundary properties
Materials Science & Technology 2019 (MS&T2019)
2019年09月29日, 口頭発表(一般)
Ensemble-based data assimilation method for phase-field simulation of binary alloy solidification
The 4th International Symposium on Phase‑Field Modelling in Materials Science (PF19)
2019年07月22日, ポスター発表
Multi-phase-field modelling of void migration caused by electromigration in bamboo interconnect line
The 4th International Symposium on Phase‑Field Modelling in Materials Science (PF19)
2019年07月22日, ポスター発表
EnKF-based data assimilation for multi-phase-field simulation of grain growth
International Conference on Computational & Experimental Engineering and Sciences (ICCES 2019)
2019年03月25日, ポスター発表
Large scale phase-field crystal simulation of polycrystalline grain growth using GPU supercomputer
2019 TMS Annual Meeting & Exhibition
2019年03月10日, ポスター発表
Prediction of biaxial tensile deformation behavior of aluminum alloy using crystal plasticity finite element method and machine learning
2019 TMS Annual Meeting & Exhibition
2019年03月10日, ポスター発表
Cyclic austenite-to-ferrite and ferrite-to-austenite phase transformations in Fe-C-Mn-Si alloy: Phase-field and experimental studies
2019 TMS Annual Meeting & Exhibition
2019年03月10日, ポスター発表
Multi-phase-field simulation of electromigration in polycrystalline interconnect line
2019 TMS Annual Meeting & Exhibition
2019年03月10日, ポスター発表
Material parameter estimation for phase-field model of binary alloy solidification using EnKF-based data assimilation
2019 TMS Annual Meeting & Exhibition
2019年03月10日, ポスター発表
フェーズフィールド法によるミクロ組織形成シミュレーション
一般社団法人 日本熱処理技術協会 平成30年度 第4回熱処理技術セミナー
2019年01月25日, 口頭発表(招待・特別)
Prediction of Biaxial Tensile Deformation Behavior of Aluminum Alloy Sheets using Crystal Plasticity Finite Element Method and Machine Learning
The 9th International Conference on Multiscale Materials Modeling (MMM2018)
2018年10月28日, 口頭発表(一般)
Estimation of Grain Boundary Anisotropy using Multi-phase-field Model based on the Ensemble Kalman Filter
The 9th International Conference on Multiscale Materials Modeling (MMM2018)
2018年10月28日, 口頭発表(一般)
Grain Growth at the Nanoscale: The Coupling of Stress and Grain Boundary Motion
The 9th International Conference on Multiscale Materials Modeling (MMM2018)
2018年10月28日, 口頭発表(一般)
Solidification analysis by non-equilibrium phase field model using thermodynamics data estimated by machine learning
The 9th International Conference on Multiscale Materials Modeling (MMM2018)
2018年10月28日, 口頭発表(一般)
Design of neural network for thermodynamics data of non-equilibrium multiphase field model
The 9th International Conference on Multiscale Materials Modeling (MMM2018)
2018年10月28日, 口頭発表(一般)
Two-dimensional Simulation of Cyclic Phase Transformation in Fe-C-Mn-Si Alloy using Non-equilibrium Multi-Phase-Field Model
The 9th International Conference on Multiscale Materials Modeling (MMM2018)
2018年10月28日, 口頭発表(一般)
Parameter Estimation for Multi-phase-field Simulation using Ensemble Kalman Filter
The 4th International Congress on 3D Materials Science (3DMS) 2018
2018年06月10日, 口頭発表(一般)
Multi-phase-field Simulation of Austenite-to-ferrite Transformation in Fe-C-Mn and Fe-C-Mn-Si Alloys
The 5th International Symposium on Steel Science (ISSS2017)
2017年10月01日, 口頭発表(招待・特別)
Three-dimensional phase-field simulation of mechano-electrochemical behavior in LiCoO2 and solid electrode
232nd ECS Fall Meeting 2017
2017年10月01日, 口頭発表(一般)
Phase-Field Modeling of pH-Dependent Corrosion Reactions at an Iron/Aqueous Solution Interface
232nd ECS Fall Meeting 2017
2017年10月01日, 口頭発表(一般)
Three-dimensional phase-field crystal simulation of grain boundary migration, grain rotation and grain translation in crystals
4th World Congress on Integrated Computational Materials Engineering (ICME 2017)
2017年05月21日, 口頭発表(一般)
Effect of Mn diffusivity on the austenite-to-ferrite transformation behavior in Fe-C-Mn ternary alloy: A Multi-phase-field study
4th World Congress on Integrated Computational Materials Engineering (ICME 2017)
2017年05月21日, 口頭発表(一般)
Parameter Estimation for Two-dimensional Phase-field Simulation using Ensemble Kalman Filterassumption
4th World Congress on Integrated Computational Materials Engineering (ICME 2017)
2017年05月21日, 口頭発表(一般)
Solidification simulation of Fe-Cr-Ni-Mo-C duplex stainless steel using CALPHAD-coupled multi-phase-field model based on non-equal diffusion potential assumption
4th World Congress on Integrated Computational Materials Engineering (ICME 2017)
2017年05月21日, 口頭発表(一般)
Nano simulation study of mechanical property parameter for microstructure-based multiscale simulation
4th World Congress on Integrated Computational Materials Engineering (ICME 2017)
2017年05月21日, 口頭発表(一般)
Development of Microstructure-based Multiscale Simulation Process for Hot Rolling of Duplex Stainless Steel
4th World Congress on Integrated Computational Materials Engineering (ICME 2017)
2017年05月21日, 口頭発表(一般)
Numerical Biaxial Tensile Test of Aluminum Alloy Sheets using Crystal Plasticity Model Implemented in Commercial FEM software
The 13rd Asia-Pacific Symposium on Engineering Plasticity and Its Applications (AEPA2016)
2016年12月04日, 口頭発表(一般)
Multi-phase-field simulation of austenite-to-ferrite transformation in heat affected zone of Fe-C-Mn alloy
10th International Conference on Trends in Welding Research & 9th International Welding Symposium of Japan Welding Society
2016年10月11日, 口頭発表(一般)
Phase-Field Simulation of Li Intercalation-Induced Stress Evolution in an Elastically Imhomogeneous LiCoO2 Polycrystals
Pacific Rim Meeting on Electrochemical And Solid-state Science 2016 (PRiME2016)
2016年10月02日, 口頭発表(一般)
Three-Dimensional Phase-Field Simulation of Li Diffusion and Stress Evolution in a Polycrystalline LiCoO2 Cathode
Pacific Rim Meeting on Electrochemical And Solid-state Science 2016 (PRiME2016)
2016年10月02日, 口頭発表(一般)
粒界移動と粒回転のフェーズフィールドクリスタルシミュレーション
日本機械学会 第29回計算力学講演会
2016年09月22日, 口頭発表(一般)
2次元フェーズフィールドシミュレーションにおけるアンサンブルカルマンフィルタを用いたデータ同化
日本機械学会 第29回計算力学講演会
2016年09月22日, 口頭発表(一般)
結晶塑性有限要素法によるアルミニウム合金板の数値二軸引張試験と成形シミュレーション:オープンソースの利用と精度検証
日本機械学会 第29回計算力学講演会
2016年09月22日, 口頭発表(一般)
Fe-C-Mn-Si合金におけるγ→α変態のマルチフェーズフィールドモデリング
日本機械学会 第29回計算力学講演会
2016年09月22日, 口頭発表(一般)
Numerical biaxial tensile test for sheet metal forming simulation of aluminum alloy sheets based on the homogenized crystal plasticity finite element method
The 10th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes (NUMISHEET2016)
2016年09月04日, 口頭発表(一般)
Simulation of Solidification in Fe-Cr-Ni-Mo-C Duplex Stainless Steel Using CALPHAD-Coupled Multi-Phase-Field Model
9th Pacific Rim International Conference on Advanced Materials and Processing (PRICM9)
2016年08月01日, 口頭発表(一般)
Multiscale Modelling of Dual-phase Steel using Multi-phase-field and Crystal Plasticity Fast Fourier Transformation Methods
12th World Congress on Computational Mechanics (WCCM XII)
2016年07月24日, 口頭発表(招待・特別)
Numerical Biaxial Tensile Test of Aluminum Alloy Sheets based on Crystal Plasticity Finite Element Method
12th World Congress on Computational Mechanics (WCCM XII)
2016年07月24日, 口頭発表(一般)
Multi-Phase-Field Simulation of Cyclic Phase Transformation in Fe-C-Mn-Si Quaternary Alloy
12th World Congress on Computational Mechanics (WCCM XII)
2016年07月24日, 口頭発表(一般)
Data Assimilation of Phase-field Simulation Using Ensemble Kalman Filter: Parameter Estimation from Experimental Data
12th World Congress on Computational Mechanics (WCCM XII)
2016年07月24日, 口頭発表(一般)
3D Phase-Field Simulation of Li-ion Diffusion and Stress Evolution in LiCoO2 Electrode of Li-ion battery
12th World Congress on Computational Mechanics (WCCM XII)
2016年07月24日, 口頭発表(一般)
Grain growth in a system containing finely dispersed mobile second-phase particles: A GPU-accelerated multi-phase-field study
6th International Conference on Recrystallization and Grain Growth (REX&GG2016)
2016年07月17日, 口頭発表(一般)
GPU-accelerated 3D phase field crystal simulation of grain boundary motion in bcc bicrystal
3rd International Congress on 3D Materials Science 2016
2016年07月10日, 口頭発表(一般)
Data Assimilation for Phase-field Simulation using Ensemble Kalman Filter
3rd International Congress on 3D Materials Science 2016
2016年07月10日, 口頭発表(一般)
EnKFによるフェーズフィールド計算のデータ同化のGPU高速化
日本計算工学会第21回計算工学講演会
2016年05月31日, 口頭発表(一般)
BCC鉄における結晶粒成長のフェーズフィールドクリスタルシミュレーション
日本計算工学会第21回計算工学講演会
2016年05月31日, 口頭発表(一般)
ナノシミュレーションによるFe-Ni-Cr-C合金の弾性定数の研究
日本計算工学会第21回計算工学講演会
2016年05月31日, 口頭発表(一般)
マルチフェーズフィールド法によるミクロ組織予測を中核としたステンレス2相鋼熱間圧延のマルチスケール解析手法の開発
日本計算工学会第21回計算工学講演会
2016年05月31日, 口頭発表(一般)
3D Simulation of Static Recrystallization and Phase Transformation using Multi-phase-field and Crystal Plasticity Fast Fourier Transformation Methods
2nd International Workshop on Software Solutions for ICME (ICMEg2016)
2016年04月12日, 口頭発表(一般)
Microstructure-based Multiscale Analysis of Hot Rolling of Duplex Stainless Steel by using Various Simulation Software
2nd International Workshop on Software Solutions for ICME (ICMEg2016)
2016年04月12日, 口頭発表(一般)
Nano simulation study of elastic constant in Fe-Ni-Cr alloy doped C
2nd International Workshop on Software Solutions for ICME (ICMEg2016)
2016年04月12日, 口頭発表(一般)
LiCoO2 正極材料内の応力変化の 3 次元 Phase-field シミュレーション
電気化学会第83回大会
2016年03月29日, 口頭発表(一般)
Fe-C-Mn系における γ→α 変態挙動のCALPHAD法と連成したMulti-Phase-Field シミュレーション
日本鉄鋼協会 第171回春季講演大会
2016年03月23日, 口頭発表(一般)
均質化結晶塑性有限要素法によるIF 鋼の数値二軸引張試験と実験的検証
日本鉄鋼協会 第171回春季講演大会
2016年03月23日, 口頭発表(一般)
Adjoint based data assimilation for phase field model using second order information of a posterior distribution
American Physical Society March Meeting
2016年03月16日, 口頭発表(一般)
結晶塑性有限要素法による6000系アルミニウム合金板の成形シミュレーション
日本機械学会M&M2015
2015年11月21日, 口頭発表(一般)
均質化結晶塑性有限要素法によるIF鋼の数値二軸引張試験
日本機械学会M&M2015
2015年11月21日, 口頭発表(一般)
均質化結晶塑性有限要素法による5000系アルミニウム合金板材の球頭張出し成形シミュレーション
日本塑性加工学会 第66回塑性加工連合講演会
2015年10月30日, 口頭発表(一般)
結晶塑性FFT法とマルチフェーズフィールド法による鉄鋼材料の加工γ→α変態3次元シミュレーション
日本機械学会 第28回計算力学講演会
2015年10月10日, 口頭発表(一般)
可動分散粒子によるピンニングを考慮した多結晶粒成長の3次元マルチフェーズフィールドシミュレーション
日本機械学会 第28回計算力学講演会
2015年10月10日, 口頭発表(一般)
フェーズフィールドシミュレーションへのアンサンブルカルマンフィルタの実装
日本機械学会 第28回計算力学講演会
2015年10月10日, 口頭発表(一般)
計算コストの大きいモデルに対するデータ同化手法の開発 ~フェーズフィールドモデルを例として~
日本機械学会 第28回計算力学講演会
2015年10月10日, 口頭発表(一般)
2次元非平衡マルチフェーズフィールドモデルを用いたFe-Cr-Ni-Mo-C系ステンレス鋼凝固計算プログラムの開発
日本機械学会 第28回計算力学講演会
2015年10月10日, 口頭発表(一般)
非平衡マルチフェーズフィールドモデルを用いたFe-C-Mn合金におけるγ→α変態の2次元シミュレーション
日本機械学会 第28回計算力学講演会
2015年10月10日, 口頭発表(一般)
急加圧を受ける空孔を有するマクスウェル粘弾性体におけるき裂の進展
日本機械学会 第28回計算力学講演会
2015年10月10日, 口頭発表(一般)
Large-scale Multi-phase-field Simulation of Polycrystalline Grain Growth with Finely Dispersed ParticlesFinite Element Method
Materials Scince & Technology 2015
2015年10月06日, 口頭発表(一般)
Identification of Yield Function for 5000 Series Aluminum Alloy Sheet by Numerical Biaxial Tensile Testing using Homogenized Crystal Plasticity Finite Element Method
Materials Scince & Technology 2015
2015年10月05日, 口頭発表(一般)
Fe-C-Mn-X 4元系合金におけるγ→α変態の非平衡マルチフェーズフィールドシミュレーション
日本鉄鋼協会 第170回秋季講演大会 学生ポスターセッション
2015年09月16日, 口頭発表(一般)
マルチフェーズフィールド法による可動分散粒子が結晶粒成長に及ぼす影響の評価
日本鉄鋼協会 第170回秋季講演大会 学生ポスターセッション
2015年09月16日, 口頭発表(一般)
Simulation of Austenite-to-Ferrite Transformation in Fe-C-Mn Alloy using Non-equilibrium Multi-Phase-Field Model Coupled with CALPHAD Database
International Conference on Solid-Solid Phase Transformations in Inorganic Materials
2015年06月28日, 口頭発表(一般)
3D Modeling of Ferrite Transformation in Deformed-austenite using Multi-Phase-Field Method and Crystal Plasticity Fast Fourier Transformation Method
International Conference on Solid-Solid Phase Transformations in Inorganic Materials
2015年06月28日, 口頭発表(一般)
多結晶粒成長過程における析出物によるピンニングの大規模マルチフェーズフィールドシミュレーション
日本計算工学会第20回計算工学講演会
2015年06月08日, 口頭発表(一般)
Fe-C-Mn合金のα+γ2相域における繰返し変態挙動のマルチフェーズフィールドシミュレーション
日本計算工学会第20回計算工学講演会
2015年06月08日, 口頭発表(一般)
非平衡マルチフェーズフィールドモデル2次元計算手法の開発
日本計算工学会第20回計算工学講演会
2015年06月08日, 口頭発表(一般)
Prediction of 3D Microstructure and Plastic Deformation Behavior in Dual-Phase Steel using Multi-Phase-Field and Crystal Plasticity FFT Methods
18th ESAFORM International Conference on Material Forming
2015年04月15日, 口頭発表(一般)
マルチフェーズフィールド法を用いた多結晶粒成長におけるピンニング効果の大規模計算
日本鉄鋼協会 第169回春季講演大会 学生ポスターセッション
2015年03月18日, 口頭発表(一般)
Fe-C-X3元系合金におけるγ→α変態のマルチフェーズフィールドシミュレーション
日本鉄鋼協会 第169回春季講演大会 学生ポスターセッション
2015年03月18日, 口頭発表(一般)
Large-scale Multi-Phase-Field Simulation of Abnormal Polycrystalline Grain Growth using TSUBAME2.5 GPU-Supercomputer
SIAM Conference on Comutational Science and Engineering
2015年03月14日, 口頭発表(一般)
Large-scale Multi-Phase-Field Simulation of Abnormal Polycrystalline Grain Growth using TSUBAME2.5 GPU-Supercomputer
SIAM Conference on Comutational Science and Engineering
2015年03月14日, 口頭発表(一般)
ジルコニウムの塑性変形挙動の結晶塑性有限要素解析
日本機械学会 第27回計算力学講演会
2014年11月22日, 口頭発表(一般)
非平衡MPFモデルによる多元合金鋼のγ→α変態シミュレーション
日本機械学会 第27回計算力学講演会
2014年11月22日, 口頭発表(一般)
非平衡界面フェーズフィールドモデルの安定化手法
日本機械学会 第27回計算力学講演会
2014年11月22日, 口頭発表(一般)
動的フェライト変態のマルチフェーズフィールドモデリング
日本機械学会 第27回計算力学講演会
2014年11月22日, 口頭発表(一般)
アルミニウム合金板の二軸引張変形の均質化結晶塑性有限要素解析と実験検証
日本機械学会 第27回計算力学講演会
2014年11月22日, 口頭発表(一般)
均質化結晶塑性有限要素法による5000系アルミニウム合金板の数値二軸引張試験
軽金属学会 第127回秋期大会
2014年11月15日, 口頭発表(一般)
成形シミュレーションの高精度化に資する結晶塑性解析技術
軽金属学会 第127回秋期大会
2014年11月15日, 口頭発表(一般)
結晶塑性FFT法を用いたDP鋼の3次元イメージベース変形挙動解析
日本塑性加工学会 第65回塑性加工連合講演会
2014年10月11日, 口頭発表(一般)
均質化結晶塑性有限要素法による5000系アルミニウム合金板の二軸引張変形挙動解析
日本塑性加工学会 第65回塑性加工連合講演会
2014年10月11日, 口頭発表(一般)
DP鋼の単軸引張変形における応力・ひずみ分配挙動の結晶塑性FFTシミュレーション
日本鉄鋼協会 第168回秋季講演大会
2014年09月24日, 口頭発表(一般)
熱力学データベースと連携した非平衡マルチフェーズフィールドも出るを用いたFe-C-Mn合金のγ-α変態シミュレーション
日本鉄鋼協会 第168回秋季講演大会
2014年09月24日, 口頭発表(一般)
Multi-Phase-Field Analysis of Stress-Strain Curve and Ferrite Grain Formation during Dynamic Strain-induced Ferrite Transformation
The 8th Asia-Pacific Conference on Engineering Plasticity and Its Applications
2014年09月03日, 口頭発表(一般)
3D Microstructure-based Simulation of Plastic Deformation in Dual-phase Steel using Multi-Phase-Field and Crystal Plasticity Fast Fourier Transformation Methods
3rd International Symposium on Phase-field Method 2014
2014年08月26日, 口頭発表(一般)
Modelling of Biaxial Deformation Behavior in an Aluminium Alloy Sheet using Homogenized Crystal Plasticity Finite Element Method
11th World Congress on Computational Mechanics
2014年07月20日, 口頭発表(一般)
Extreme Large-scale Multi-Phase-Field Simulation of Polycrystalline Grain Growth using TSUBAME2.5 GPU-Supercomputer
11th World Congress on Computational Mechanics
2014年07月20日, 口頭発表(一般)
Large Scale 3D Multi-phase-field Simulation of Microstructure Evolution using TSUBAME2.5 GPU-supercomputer
International Congress on 3D Materials Science 2014
2014年06月29日, 口頭発表(一般)
Simulation of Stress and Strain Partitioning in Dual-phase Steel using Multi-Phase-Field and Crystal Plasticity FFT Methods
1st International Workshop on Software Solutions for ICME
2014年06月24日, 口頭発表(一般)
GPUスパコンを用いたフェライト変態の大規模マルチフェーズフィールドシミュレーション
日本計算工学会 第19回計算工学講演会
2014年06月11日, 口頭発表(一般)
熱力学データベースを用いたγ→α変態のマルチフェーズフィールドシミュレーション
日本計算工学会 第19回計算工学講演会
2014年06月11日, 口頭発表(一般)
TSUBAME 2.5スーパーコンピューターを用いたFe-C合金中で生じる
オーステナイト-フェライト変態挙動の大規模マルチフェーズフィールドシミュレーション
日本鉄鋼協会 第167回春季講演大会
2014年03月21日, 口頭発表(一般)
動的フェライト変態のマルチフェーズフィールドモデリング
日本機械学会関東支部第20期講演会
2014年03月14日, 口頭発表(一般)
Three-dimensional Multi-Phase-Field Simulation of Orientation-dependent Ferrite Grain Growth in Steel
5th Asia Pacific Congress on Computational Mechanics (APCOM2013)
2013年12月11日, 口頭発表(基調)
Image-based Numerical Tensile Test of Dual-Phase Steel using Homogenized Crystal Plasticity Finite Element and Multi-Phase-Field Methods
5th Asia Pacific Congress on Computational Mechanics (APCOM2013)
2013年12月11日, 口頭発表(一般)
Large-scale Multi-Phase-Field Simulation of Austenite-to-Ferrite Transformation in Fe-C Alloy using GPU-cluster Computer
5th Asia Pacific Congress on Computational Mechanics (APCOM2013)
2013年12月11日, 口頭発表(一般)
Ferrite Transformation Behavior in Deformed Austenite During Continuous
5th Asia Pacific Congress on Computational Mechanics (APCOM2013)
2013年12月11日, 口頭発表(一般)
GPUスパコンTSUBAMEによるデンドライト淘汰現象のphase-fieldシミュレーション
日本機械学会 第26回計算力学講演会
2013年11月01日, 口頭発表(一般)
結晶塑性有限要素法とマルチフェーズフィールド法によるDual-Phase鋼の塑性変形挙動の組織形態依存性評価
日本機械学会 第26回計算力学講演会
2013年11月01日, 口頭発表(一般)
多結晶粒成長の大規模マルチフェーズフィールドシミュレーション ~GPUスパコンTSUBAME 2.0への実装~
日本機械学会 第26回計算力学講演会
2013年11月01日, 口頭発表(一般)
多結晶粒成長における応力場発展のフェーズフィールド微視的弾性解析
日本機械学会 第26回計算力学講演会
2013年11月01日, 口頭発表(一般)
Multi-Phase-Field Simulation of Austenite-to-Ferrite Transformation in Steel Accelerated by Multiple-GPU Computing
The 8th Pacific Rim International Conference on Advanced Materials and Processing (PRICM8)
2013年08月04日, 口頭発表(一般)
マルチフェーズフィールドシミュレーションの複数GPU計算
日本計算工学会 第18回計算工学講演会
2013年06月19日, 口頭発表(一般)
GPUによるMulti-Phase-Fieldシミュレーションの高速化評価
日本機械学会 第25回計算力学講演会
2012年10月06日, 口頭発表(一般)