Papers - Shizawa, Kazuyuki

Mathisson-Papapetrou force on wedge disclinations

Yuan, C., Lei, X., Tsuchida S., Fujii, T., Shizawa, K.

Acta Mechanica Sinica (Springer Nature)  41 ( 4 ) 424637_1 - 424637_13 2026.04

Research paper (scientific journal), Joint Work, Last author, Accepted

　View Summary

In this study, we derive a more generalized form of the Mathisson–Papapetrou force equation and perform an in-depth analysis of the variation in the Mathisson–Papapetrou force between two wedge disclinations across different calculation models in a two-dimensional plane. The results demonstrate that the stress field magnitude along the x<inf>1</inf> and x<inf>2</inf> axes consistently remains zero, facilitating the wedge disclination dipole in achieving equilibrium state along these two directions within the plane. Furthermore, the stress field enables the Mathisson–Papapetrou force acting on one wedge disclination in semicircular motion to be approximated by the force in linear motion within the same two-dimensional plane. This study contributes a more comprehensive understanding of wedge disclination by deriving a generalized Mathisson–Papapetrou force equation applicable to disclinations.

• Access to Document (DOI)
• Access to Document (DOI)

Mathisson–Papapetrou force on wedge disclinations

Yuan C., Lei X.W., Fujii T., Shizawa K.

Acta Mechanica Sinica Lixue Xuebao 42 ( 4 )  2026.04

ISSN  05677718

　View Summary

In this study, we derive a more generalized form of the Mathisson–Papapetrou force equation and perform an in-depth analysis of the variation in the Mathisson–Papapetrou force between two wedge disclinations across different calculation models in a two-dimensional plane. The results demonstrate that the stress field magnitude along the x<inf>1</inf> and x<inf>2</inf> axes consistently remains zero, facilitating the wedge disclination dipole in achieving equilibrium state along these two directions within the plane. Furthermore, the stress field enables the Mathisson–Papapetrou force acting on one wedge disclination in semicircular motion to be approximated by the force in linear motion within the same two-dimensional plane. This study contributes a more comprehensive understanding of wedge disclination by deriving a generalized Mathisson–Papapetrou force equation applicable to disclinations.

• Access to Document (DOI)

Dislocation-based crystal plasticity simulation on grain-size dependence of mechanical properties in dual-phase steels

Suzuki M., Shizawa K., Muramatsu M.

International Journal of Solids and Structures 323 2025.12

ISSN  00207683

　View Summary

In this study, the effect of ferrite grain size on the mechanical properties and dislocation behavior of dual-phase (DP) steel is investigated using dislocation-based crystal plasticity finite element analysis. DP steel, composed of a soft ferritic phase and a hard martensitic phase, shows mechanical properties that are significantly influenced by ferrite grain size. The mechanism underlying this grain size effect is clarified by analyzing the partitioning and distribution of stress, strain, and dislocations in each phase. Three models with the same volume fraction of martensitic phase but different ferrite grain sizes are subjected to tensile loading. Interestingly, even though only the ferrite grain size is changed, the stress in the martensitic phase exhibited a notable dependence on ferrite grain size. This can be explained as follows. Geometrically necessary (GN) dislocations accumulate on the ferrite side of the ferrite–martensite grain boundary, and the grain boundary occupancy per unit area increases as the ferrite grain size decreases. As a result, smaller ferrite grain sizes make the ferritic phase less deformable owing to the effect of GN dislocations, shifting more deformation to the martensitic phase. This behavior is confirmed by the more uniform strain distribution and partitioning observed with decreasing ferrite grain size. As the martensitic phase takes on greater deformation, the statistically stored dislocation density in the martensitic phase becomes ferrite grain size dependent, which in turn leads to the observed grain size dependence of stress in the martensitic phase.

• Access to Document (DOI)

Dislocation-based crystal plasticity simulation on grain size dependence of mechanical properties in dual-phase steel

Suzuki,M., Shizawa, K. and Muramatsu, M.

International Journal of Solids and Structures (Elsevier)  323   113634_1 - 113634_12 2025.12

Research paper (scientific journal), Joint Work, Last author, Accepted

　View Summary

In this study, the effect of ferrite grain size on the mechanical properties and dislocation behavior of dual-phase (DP) steel is investigated using dislocation-based crystal plasticity finite element analysis. DP steel, composed of a soft ferritic phase and a hard martensitic phase, shows mechanical properties that are significantly influenced by ferrite grain size. The mechanism underlying this grain size effect is clarified by analyzing the partitioning and distribution of stress, strain, and dislocations in each phase. Three models with the same volume fraction of martensitic phase but different ferrite grain sizes are subjected to tensile loading. Interestingly, even though only the ferrite grain size is changed, the stress in the martensitic phase exhibited a notable dependence on ferrite grain size. This can be explained as follows. Geometrically necessary (GN) dislocations accumulate on the ferrite side of the ferrite–martensite grain boundary, and the grain boundary occupancy per unit area increases as the ferrite grain size decreases. As a result, smaller ferrite grain sizes make the ferritic phase less deformable owing to the effect of GN dislocations, shifting more deformation to the martensitic phase. This behavior is confirmed by the more uniform strain distribution and partitioning observed with decreasing ferrite grain size. As the martensitic phase takes on greater deformation, the statistically stored dislocation density in the martensitic phase becomes ferrite grain size dependent, which in turn leads to the observed grain size dependence of stress in the martensitic phase.

• Access to Document (DOI)
• Access to Document (DOI)

Deep learning-aided inverse analysis framework to accelerate the exploration of DP steel microstructures

Suzuki M., Shizawa K., Muramatsu M.

Materials Today Communications 41 2024.12

　View Summary

Materials development requires numerous numbers of trial and error experiments. To reduce the experimental cost, numerical simulations which predict material microstructures and mechanical properties have a great potential to estimate the microstructures that should be produced for obtaining materials with the desired properties. There is a need to develop dual-phase (DP) steel with higher strength and ductility because DP steel is widely used due to its significant mechanical properties. DP steel consists of a soft phase (ferrite) and a hard phase (martensite), and the mechanical properties depend on the ratio of the two phases. The mechanical properties of DP steels are affected by the spatial distribution of martensite and ferrite, which requires a comprehensive consideration of a variety of microstructures. The problem is how to estimate microstructures of DP steel with the desired mechanical property because a comprehensive investigation of microstructures makes computational cost significantly expensive. For the purpose of reduction of the computational costs, we aim to develop a framework with low computational cost. The developed framework finds the optimal microstructure of DP steel by repeated random searches for a model that combines a generative adversarial network (GAN), which generates microstructures, and a convolutional neural network (CNN), which predicts the maximum stress and working limit strain from microstructures. Due to a low-dimensional search space provided by a latent variable of GAN, the proposed framework enables an efficient search for microstructures possible. To explore the desired microstructures under complex deformation modes, the multiple deformation modes are considered in this study. This framework is applicable not only for the microstructure of DP steel but also any other material microstructures. We are exhaustively able to explore the microstructure with desired properties of metallic or other composite materials in low-dimensional space thanks to this framework and contributes to accelerating materials development.

• Access to Document (DOI)

Disclination-based crystal plasticity FE analysis for influence of kink formation and grain size on material strength in dual-phase Mg alloy with LPSO phase

小倉和也, 池隼佑, 志澤一之

材料 (日本材料学会)  72 ( 11 ) 790 - 797 2023.11

Research paper (scientific journal), Joint Work, Accepted,  ISSN  05145163

　View Summary

Dual-phase Mg alloys consisting of α-Mg phase and LPSO phase are attracting attention as structural materials of next-generation because of its high specific strength and relatively high ductility. These alloys have excellent mechanical properties attributed to kink deformation and grain refinement based on dynamic recrystallization. However, the influence of kink formation and difference in grain size on material strength of the alloys has never been clarified computationally. In this paper, a crystal plasticity Cosserat model is newly developed considering disclination density to take account of information of rotational crystal defect important for kink formation. Using the preset model, a two-dimensional FE analysis is performed for a rectangular three-crystal plate and a polycrystalline plate of the dual-phase Mg alloys with LPSO phase. Through such computation, the effects of shape of kink band and recrystallized grain size of α-Mg phase on change in material strength are numerically predicted in the process of reverse loading after compression one.

• Access to Document (DOI)

Current Status and Issues of Crystal Plasticity Model

Shizawa K.

Journal of the Japan Society for Technology of Plasticity 6 ( 61 ) 1 - 2 2023

ISSN  00381586

• Access to Document (DOI)

Multiphysics Crystal Plasticity Analysis

Shizawa K.

Journal of the Japan Society for Technology of Plasticity 6 ( 61 ) 9 - 12 2023

ISSN  00381586

• Access to Document (DOI)

Development of phase-field model based on balance laws and thermodynamic discussion

Muramatsu M., Shizawa K.

AIP Advances (AIP Advances)  10 ( 9 )  2020.09

Research paper (scientific journal), Joint Work, Accepted

　View Summary

© 2020 Author(s). In this work, a phase-field model for recrystallization is developed based on the conservation laws. There has been no attempt to develop a phase-field model of recrystallization based on the conservation laws, even though various phase-field simulation models to reproduce the recrystallization phenomenon have been proposed. However, it is unclear what conservation laws are required for such a model. In the previous paper, toward solving this problem, we developed conservation laws of mass, momentum, angular momentum, and energy and a law of entropy at the lattice scale for the process of recrystallization. In this paper, first, two continuous variables, i.e., the order parameter and crystal orientation, are introduced into the balance equation of mass for a single phase and that of angular momentum for the lattice, respectively. Next, the fluxes of the order parameter and crystal orientation are derived from the law of entropy by the use of rational thermodynamics. Moreover, the diffusion coefficient and mass source are modeled to derive the evolution equations, i.e., phase-field equations of the order parameter and crystal orientation. Finally, for the phase-field equation of the crystal orientation, neglecting the conservative part and integrating the equation with respect to time under the first-order approximation, a phase-field model that is used for stable calculations is developed. This work aims to develop a phase-field theory on the basis of the change in crystal lattice during recrystallization. This paper gives a physical background to the methodological phase-field approach in the case of recrystallization.

• Access to Document (DOI)

Modelling and simulation of dynamic recrystallisation based on multi-phase-field and dislocation-based crystal plasticity models

Kujirai S., Shizawa K.

Philosophical Magazine (Philosophical Magazine)  100 ( 16 ) 2106 - 2127 2020.04

Research paper (scientific journal), Joint Work, Accepted,  ISSN  14786435

　View Summary

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. The mechanical properties of metals used as structural materials are significantly affected by hot (or warm) plastic working. Therefore, it is industrially important to predict the microscopic behaviour of materials in the deformation process during heat treatment. In this process, a number of nuclei are generated in the vicinity of grain boundaries owing to thermal fluctuation or the coalescence of subgrains, and dynamic recrystallisation (DRX) occurs along with the deformation. In this paper, we develop a DRX model by coupling a dislocation-based crystal plasticity model and a multi-phase-field (MPF) model through the dislocation density. Then, the temperature dependence of the hardening tendency in the recrystallisation process is introduced into the DRX model. A multiphysics simulation for pure Ni is conducted, and then the validity of the DRX model is investigated by comparing the numerical results of microstructure formation and the nominal stress–strain curve during DRX with experimental results. The obtained results indicate that in the process of DRX, nucleation and grain growth occur mainly around grain boundaries with high dislocation density. As deformation progresses, new dislocations pile up and subsequent nucleation occurs in the recrystallised grains. The influence of such microstructural evolution appears as oscillation in the stress–strain curve. From the stress–strain curves, the temperature dependence in DRX is observed mainly in terms of the yield stress, the hardening ratio, and the change in the hardening tendency after nucleation occurs.

• Access to Document (DOI)

Multi-phase-field モデルおよび転位-結晶塑性モデルに基づくLPSO 型Mg二相合金に対する動的再結晶シミュレーション

鯨井翔, 志澤一之

日本機械学会論文集 (日本機械学会)  86 ( 882 ) 1 - 18 2020.02

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

Crystal plasticity FE simulation for kink band formation in Mg-based LPSO phase using dislocation-based higher-order stress model

Kimura, Y., Ueta, R. and Shizawa, K.

Mechanical Engineering Journal (The Japan Society of Mechanical Engineers)  7 ( 4 ) 1 - 19 2020.02

Research paper (scientific journal), Joint Work, Accepted

　View Summary

The dislocation-based crystal plasticity model considering higher-order stress has been constructed and a finite element (FE) analysis is conducted for both a single crystal and polycrystal with a long-period stacking ordered (LPSO) phase on the basis of the obtained model. The mesh dependence of the kink band formation is discussed from the viewpoints of the strain gradient, size effect and higher-order boundary condition. Then, it is shown that the mesh dependence of kink deformation in the FE analysis can be removed even when the scale ratio is relatively small. The width of the kink band is determined by the intrinsic length scale. When the kink band occurs in the entire specimen, work hardening can be reproduced by appropriately defining the boundary conditions for slip. The effect of the micro-scale ratio on the kink deformation is small. The disclination quadrupole structure in the kink band can be expressed qualitatively by using the incompatibility of crystal slip. Moreover, it is shown the back stress behaves as the resistance to the slip deformation in a polycrystal consisting of LPSO phases in shape of rectangular strip.

• Access to Document (DOI)

FE simulation on kink band formation of magnesium-based LPSO phase using dislocation-crystal plasticity model based on higher-order stress theory

SHIZAWA K.

Keikinzoku/Journal of Japan Institute of Light Metals (Keikinzoku/Journal of Japan Institute of Light Metals)  70 ( 5 ) 204 - 211 2020

ISSN  04515994

• Access to Document (DOI)

Analysis of shear fatigue properties of iron single crystals regarding possible effects of the resolved normal stresses on the slip planes

Hayakawa M., Nakayama E., Okamura K., Yamamoto M., Shizawa K.

Materials Today Communications (Elsevier)  21 2019.12

Research paper (scientific journal), Joint Work, Accepted

　View Summary

© 2019 Elsevier Ltd Crystal orientation effects on the shear fatigue limits of iron single-crystals were investigated by considering the influence of normal stress of the slip plane on the critical resolved shear stress (CRSS). The shear fatigue limit with the (123) plane in the shear loading position was experimentally confirmed to exceed that with shear loading on the (110) plane. On the contrary, the shear yield stress of the (123) plane, evaluated by monotonic shear tests, was lower than that of the (110) plane. To solve this seeming contradiction, it was postulated that body-centred cubic crystals possessed 24 slip systems and that the CRSS was sensitive to the resolved normal stress (RNS) on the slip plane. That is, it was assumed that the CRSS decreased under the tensile RNS according to its magnitude, but increased under the compressive RNS. The mathematical model of the CRSS dependence on the RNS was simply introduced to the work-hardening law proposed by Peirce et al. allowing formulation of the algebraic equations yielding the crystalline slip rates. This crystal plasticity model was applied to analyse monotonic shear and shear fatigue tests. By considering the effect of the RNS sensitivity, the shear yield stress with the (123) plane in the shear loading position was calculated to be lower than that with the (110) plane, showing agreement with the experimental results of the monotonic shear tests. Furthermore, in the application of cyclic shear loads corresponding to the fatigue limits, it was confirmed that the plastic strain range of the primary slip plane converged to similar values despite the differences in the crystal orientations of the shear plane and the normal stresses to it. These results imply that the present method allows the prediction of fatigue limits under different crystal orientations and loading conditions.

• Access to Document (DOI)

高次応力モデルを用いたMg基LPSO相の寸法効果に対する転位-結晶塑性FEM解析

木村祐一, 上田亮, 志澤一之

材料 (日本材料学会)  68 ( 11 ) 825 - 832 2019.11

Research paper (scientific journal), Joint Work, Accepted

Discrete conservation laws based on micropolar theory considering lattice-scale-director during phase transformation

M. Muramatsu, K. Shizawa

AIP Advances (AIP Publishing)  9 ( 085211 ) 1 - 15 2019.08

Research paper (scientific journal), Joint Work, Accepted

　View Summary

© 2019 Author(s). In this paper, the conventional conservation laws are formulated by modeling the lattice behavior during phase transformation as the rotation of a director. More precisely, a crystal lattice in a metal is modeled during the recrystallization process as an elastic bar element subject to stretching. Using this model, the discrete conservation laws for micropolar theory are finally derived. These conservation laws are the basis of the governing equations of Kobayashi-Warren-Carter (KWC)-type phase-field models. Hence, the derivation of this theory is significant in gaining a deeper comprehension of KWC-type phase-field models. First, balance laws for the mass, momentum, angular momentum, and energy of a lattice element are formulated. These laws are summed over a phase in a representative volume element (RVE) and averaged over the RVE. This enables the development of macroscopic balance laws for a continuum mixture consisting of several phases. When the RVE is reduced to a material point in the final formulation, the present model can be regarded as a director model whose direction vector expressing the crystal orientation is attached to a material point of a simple body. By performing an order estimation, the balance law of angular momentum can be separated into bulk and lattice parts. The bulk part results in the usual form and the latter corresponds to the evolution equation of the crystal orientation in a KWC-type phase-field model.

• Access to Document (DOI)

Crystal plasticity FE simulation for size effect of Mg-based LPSO phase using dislocation-based higher-order stress model

Kimura Y., Ueta R., Shizawa K.

Zairyo/Journal of the Society of Materials Science, Japan (Zairyo/Journal of the Society of Materials Science, Japan)  68 ( 11 ) 825 - 832 2019

ISSN  05145163

　View Summary

©2019 The Society of Materials Science, Japan The dislocation-based crystal plasticity model has been extended to a model considering higher-order stress by explicitly considering the mechanical work induced by the strain gradient. Furthermore, a finite element (FE) analysis is performed for a single crystal with a long-period stacking ordered (LPSO) phase on the basis of the obtained model. The mesh dependence of the kink band formation is discussed from the viewpoints of the strain gradient, size effect and higher-order boundary condition. Then, it is shown that the mesh dependence of kink deformation in the FE analysis can be removed even when the size effect parameter is relatively small. The width of the kink band is determined by the intrinsic length scale. When the kink band occurs in the entire specimen, work hardening can be reproduced by appropriately defining the boundary conditions for slip. The effect of length scale ratio on the kink deformation is small. Moreover, it is shown that the disclination quadrupole structure in the kink band can be expressed qualitatively by using incompatibility of crystal slip.

• Access to Document (DOI)

Dislocation-based crystal plasticity FE analysis for kink band formation in Mg-based LPSO phase considering higher-order stress

Kimura Y., Ueta R., Shizawa K.

Procedia Manufacturing (Procedia Manufacturing)  15   1825 - 1832 2018

　View Summary

© 2018 The Authors. Published by Elsevier B.V. An FE analysis has been performed for a single crystal of long-period stacking ordered phase on the basis of the dislocation-based crystal plasticity model considering higher-order stress. The mesh dependence on the kink band formation has been discussed from the viewpoint of the strain gradient and size effect. Then, it is shown that the mesh dependence of kink deformation in the FE analysis can be removed even when the scale ratio is relatively small. Moreover, it is indicated that the disclination quadrupole structure in the kink band can be expressed qualitatively by use of the incompatibility of crystal slip.

• Access to Document (DOI)

Evaluating Microscopic Hardness in Ferritic SteelBased on Crystallographic Measurements via Electron Backscatter Diffraction

Hayakawa, M., Tomatsu, K., Nakayama, E., Okamura, K., Yalnamoto, M. and Shizawa, K

Materials Science and Engineering A (Elsevier)  700   281 - 290 2017.07

Research paper (conference, symposium, etc.), Joint Work, Accepted

• Access to Document (DOI)

Multiscale Simulation of Dynamic Recrystallization for α-Mg Phase in Mg/LPSO Alloys Based on Multi-phase-field and Dislocation-based Crystal Plasticity Models

Kimura, Y., Kujirai, S., Ueta, R. and Shizawa, K.

Key Engineering Materials (Trans Tech Publications)  725   243 - 248 2017.01

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

Development of Simulation Technology for Production of Porous Polymeric Membranes

Nada, H., Kudo, M., Takahashi, J., Yamamoto, T., Hara2, H. and Shizawa, K.

Key Engineering Materials (Trans Tech Publications)  725   261 - 266 2017.01

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

Development of Micro-Shear Fatigue Test and lts Application to Single Crystal of Pure lron

Hayakawa, M., Nakayama, E., Okamura, K., Yalnamoto, M. and SHIZAWA KAZUYUKI

Procedia Engineering (Elsevier)  160   167 - 174 2016.10

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

転位-結晶塑性シミュレーションによるMg基LPSO相単結晶におけるキンク帯形成位置の検討

SHIZAWA KAZUYUKI

材料 (日本材料学会)  65 ( 3 ) 220 - 227 2016.03

Research paper (conference, symposium, etc.), Joint Work, Accepted

Homogenized molecular chain plasticity simulation for crystalline polymer using craze evolution model based on chemical kinetics

Hara, H. and SHIZAWA KAZUYUKI

International Journal of Mechanical Sciences (Elsevier)  101   180 - 195 2015.08

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

Three-dimensional FE Analysis Using Homogenization Method for Ductile Polymers Based on Molecular Chain Plasticity Model Considering Craze Evolution

Hara, H. and SHIZAWA KAZUYUKI

Advanced Structured Materials (Springer)  64   97 - 119 2015.06

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

Mg基LPSO相単結晶におけるキンク帯形成の転位-結晶塑性シミュレーション

SHIZAWA KAZUYUKI

材料 (日本材料学会)  64 ( 4 ) 295-302 2015.04

Research paper (conference, symposium, etc.), Joint Work, Accepted

Molecular chain plasticity model similar to crystal plasticity theory based on change in local free volume and FE simulation of glassy polymer

Nada, H., Hara, H., Tadano, Y. and SHIZAWA KAZUYUKI

International Journal of Mechanical Sciences (Elsevier)  93   120 - 135 2015.02

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

A phase-field model of twinning and detwinning coupled with dislocation-based crystal plasticity for hcp metals

Kondo, R., Tadano, Y. and SHIZAWA KAZUYUKI

Computational Materials Science (Elsevier)  95   672 - 683 2014.09

Research paper (scientific journal), Joint Work, Accepted

• Access to Document (DOI)

Phase-field Simulation of Static Recrystallization Considering Nucleation from Subgrains and Nucleus Growth with Incubation Period

Muramatsu, M., Aoyagi, Y., Tadano, Y. and SHIZAWA KAZUYUKI

Computational Materials Science (Elsevier)  87   112-122 2014.03

Research paper (scientific journal), Joint Work, Accepted

反応速度論に基づくクレーズ発展式の構築および均質化分子鎖塑性モデルを用いた結晶性ポリマに対するクレーズ進展シミュレーション

HIDEYUKI HARA, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  79 ( 807 ) 1604-1619 2013.11

Research paper (conference, symposium, etc.), Joint Work, Accepted

自由体積変化に基づく非弾性応答則および均質化分子鎖塑性モデルを用いた結晶性ポリマに対するマルチスケールシミュレーション

HIDEYUKI HARA, HUMIHIKO MIZUSAWA, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  79 ( 800 ) 364-379 2013.04

Research paper (conference, symposium, etc.), Joint Work, Accepted

広ひずみ速度域に対応したクレーズ挙動のモデル化とその結晶性ポリマの破壊予測シミュレーションへの応用

JUNICHI TAHAHASHI, TOSHIHARU YAMAMOTO, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  79 ( 800 ) 380-394 2013.04

Research paper (conference, symposium, etc.), Joint Work, Accepted

Modeling and Simulation on Ultrafine-graining Based on Multiscale Crystal Plasticity Considering Dislocation Patterning

Aoyagi, Y., Kobayashi, R., Kaji, Y. and SHIZAWA KAZUYUKI

International Journal of Plasticity (Elsevier)  47   13-28 2013.01

Research paper (scientific journal), Joint Work, Accepted

双晶の組織形成を考慮したHCP結晶に対する転位-結晶塑性モデリングおよびシミュレーション

RUHO KONDO, YUICHI TADANO, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  78 ( 792 ) 1157-1172 2012.08

Research paper (conference, symposium, etc.), Joint Work, Accepted

再結晶現象に対するPhase-Fieldモデルの保存則に基づく構築

MAYU MURAMATSU, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  78 ( 791 ) 1065-1078 2012.07

Research paper (conference, symposium, etc.), Joint Work, Accepted

再結晶現象における結晶核と母相に対する混相理論としての保存則の定式化

MAYU MURAMATSU, YOSHITERU AOYAGI, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  78 ( 789 ) 742-757 2012.05

Research paper (conference, symposium, etc.), Joint Work, Accepted

Simulation on Nanostructured Metals Based on Multiscale Crystal Plasticity Considering Effect of Grain Boundary

Aoyagi, Y., Shimokawa, T., Shizawa, K. and Kaji, Y.

Materials Science Forum (Trans Tech Publications)  706-709   1751-1756 2012.01

Research paper (scientific journal), Joint Work, Accepted

再結晶現象に対する結晶格子スケールの離散的保存則の定式化

MAYU MURAMATSU, YOSHITERU AOYAGI, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  77 ( 780 ) 1304-1319 2011.08

Research paper (conference, symposium, etc.), Joint Work, Accepted

転位パターニングに基づく結晶粒超微細化に関するマルチスケール結晶塑性シミュレーション

YOSHITERU AOYAGI, RYOTARO KOBAYASHI, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  77 ( 775 ) 448-461 2011.03

Research paper (conference, symposium, etc.), Joint Work, Accepted

FCC超微細粒焼鈍材の降伏点降下現象に関するトリプルスケール転位-結晶塑性シミュレーション

EISUKE KUROSAWA, YOSHITERU AOYAGI, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  76 ( 772 ) 1547-1556 2010.12

Research paper (conference, symposium, etc.), Joint Work, Accepted

サブグレインからの核生成と核成長に関する静的再結晶Phase-Fieldシミュレーション

SHIZAWA KAZUYUKI

材料 (日本材料学会)  59 ( 11 ) 853-860 2010.11

Research paper (conference, symposium, etc.), Joint Work, Accepted

トリプルスケール結晶塑性モデリングおよび結晶粒微細化に伴う寸法効果に関するシミュレーション

EISUKE KUROSAWA, YOSHITERU AOYAGI, YUICHI TADANO, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  76 ( 764 ) 483-492 2010.04

Research paper (conference, symposium, etc.), Joint Work, Accepted

結晶性ポリマのクレイズ挙動に基づく延性破壊予測シミュレーション(クレイズの伝ぱ・成長停止モデルおよび汎用ソルバによる解析)

JUNICH TAKAHASHI, TOSHIHARU YAMAMOTO, KAZUYUKI SHIZAWA

日本機械学会論文集A編 (日本機械学会)  76 ( 764 ) 473-482 2010.04

Research paper (conference, symposium, etc.), Joint Work, Accepted

Modeling and Simulation for Ductile Fracture Prediction of Crystalline Polymer Based on Craze Behavior

Takahashi, J., Yamamoto, T. and SHIZAWA KAZUYUKI

International Journal of Mechanical Sciences (Elsevier)  52 ( 2 ) 266-276 2010.02

Research paper (scientific journal), Joint Work, Accepted

Multiscale Crystal Plasticity Simulation with Pseudo-Three-Dimensional Model on Ultrafine-Graining Based on Evolution of Dislocation Structures

Aoyagi, Y., Horibe, N. and Shizawa, K.

Materials Science Forum (Trans Tech Publications)  584-586   1057-1062 2008.08

Research paper (scientific journal), Joint Work, Accepted

A Triple-Scale Crystal Plasticity Simulation on Yield Behavior of Annealed FCC Fine-Grained Metals

Kurosawa, E., Aoyagi, Y., Tadano, Y. and Shizawa, K.

Materials Science Forum (Trans Tech Publications)  584-586   1027-1032 2008.08

Research paper (scientific journal), Joint Work, Accepted

A Phase-Field Simulation of Nucleation from Subgrain and Grain Growth in Static Recrystallization

Muramatsu, M., Tadano, Y. and Shizawa, K.

Materials Science Forum (Trans Tech Publications)  584-586   1045-1050 2008.08

Research paper (scientific journal), Joint Work, Accepted

非晶性ポリマの分子鎖多絡み点を考慮した分子鎖塑性モデルおよび変形誘起異方性に関する大変形FEM解析

HIRONORI NADA, SHIZAWA KAZUYUKI

日本機械学会論文集A編 (日本機械学会)  74 ( 743 ) 961-970 2008.07

Research paper (scientific journal), Joint Work, Accepted

A Dislocation-Crystal Plasticity Simulation on FCC Single Crystal Considering Geometrically Necessary Dislocation Density and Incompatibility

Ayagi Yoshiteru, Shizawa Kazuyuki

Journal of Computational Science and Technology 2 ( 1 ) 197-209 2008.06

Research paper (conference, symposium, etc.), Joint Work

自由体積変化を考慮した結晶塑性論的分子鎖塑性モデルに基づく非晶性ポリマの大変形シミュレーション

SHIZAWA KAZUYUKI

日本機械学会論文集A編 74 ( 737 ) 105-114 2008.01

Research paper (scientific journal), Joint Work, Accepted

自由体積変化に基づく確率論的非弾性応答則を用いた非晶性ポリマの結晶塑性論的分子鎖塑性モデル

SHIZAWA KAZUYUKI

日本機械学会論文集A編 74 ( 737 ) 97-104 2008.01

Research paper (scientific journal), Joint Work, Accepted

Multiscale Crystal Plasticity Modeling Based on Geometrically Necessary Crystal Defects and Simulation on Fine-Graining for Polycrystal

Aoyagi, Y. and Shizawa, K.

International Journal of Plasticity (Elsevier)  23 ( 6 ) 1022-1040 2007.06

Research paper (scientific journal), Joint Work, Accepted

Multiscale Modeling for Large Deformation of Glassy Polymer Based on Molecular Chain Slip Model and Probabilistic Response Law of Inelasticity

Nada, H., Abe, S. and Shizawa, K.

Key Engineering Materials (Trans Tech Publications)  340-341   1109-1114 2007

Research paper (scientific journal), Joint Work, Accepted

Multiscale Modeling and Simulation of Crystal Plasticity Based on Dislocation Patterning in Polycrystal

Yamaki, N., Aoyagi, Y. and Shizawa, K.

Key Engineering Materials (Trans Tech Publications)  340-341   205-210 2007

Research paper (scientific journal), Joint Work, Accepted

A Polycrystalline Analysis of Hexagonal Metal Based on the Homogenized Method

Tadano, Y., Kuroda, M., Noguchi, H. and Shizawa, K.

Key Engineering Materials (Trans Tech Publications)  340-341   1049-1054 2007

Research paper (scientific journal), Joint Work, Accepted

幾何学的に必要な転位密度および不適合度を考慮した転位-結晶塑性大変形シミュレーション (第2報，FCC単結晶への適用)

SHIZAWA KAZUYUKI

日本機械学会論文集A編 72 ( 723 ) 1646-1653 2006.11

Research paper (scientific journal), Joint Work, Accepted

幾何学的に必要な結晶欠陥を考慮した結晶粒超微細化に関する転位-結晶塑性シミュレーション

SHIZAWA KAZUYUKI

日本機械学会論文集A編 72 ( 720 ) 1223-1230 2006.08

Research paper (scientific journal), Joint Work, Accepted

幾何学的に必要な転位密度および不適合度を考慮した転位-結晶塑性大変形シミュレーション (第1報，GN結晶欠陥の定義およびマルチスケールモデリング)

SHIZAWA KAZUYUKI

日本機械学会論文集A編 72 ( 719 ) 1009-1017 2006.07

Research paper (scientific journal), Joint Work, Accepted

Multi-scale Modeling and Simulation of Crystal Plasticity Based on GN Crystal Defects Considering Dynamic Recovery of Dislocation

Oishi, S., Aoyagi, Y. and Shizawa, K.

Computational Methods (Springer)     557-562 2006

Research paper (scientific journal), Joint Work, Accepted

Modeling and Simulation of Crystal Plasticity Based on GN Crystal Defects for Ultrafine-Grained Metals Induced by Severe Plastic Deformation

Oishi, S., Aoyagi, Y. and Shizawa, K.

Materials Science Forum 503-504   215-220 2006

Research paper (scientific journal), Joint Work, Accepted

Dislocation-Crystal Plasticity Simulation Based on Self-Organization for Repartition of Dislocation Cell Structures and Subgrains

Yamaki, N., Aoyagi, Y. and Shizawa, K.

Materials Science Forum 503-504   989-994 2006

Research paper (scientific journal), Joint Work, Accepted

A Crystal Plasticity Analysis for Accumulations of Geometrically Necessary Dislocations and Dipoles around Shear Band

Aoyagi,Y. and Shizawa,K.

Mesoscopic Dynamics on Fracture Process and Materials Strength (Kluwer Academic Publisher)     87-96 2004.06

Research paper (conference, symposium, etc.), Joint Work, Accepted

クレイズの進展・消滅を考慮したポリマの破断予測モデルおよび大変形シミュレーション

SHIZAWA KAZUYUKI

日本機械学会論文集A編 70 ( 694 ) 810-817 2004.06

Research paper (scientific journal), Joint Work, Accepted

Thermomechanical Modeling of Shear Localization and Neck Propagation for Thermo-Viscoplastic Polymer

Murakami, D., Kobayashi,S. , Torigaki,T. and Shizawa,K.

Advanced Technology of Plasticity(2002) (Japan Society for Technology of Plasticity)  2   1609-1614 2002.10

Research paper (conference, symposium, etc.), Joint Work, Accepted

結晶塑性の理論と応用 〜結晶の大変形から転位蓄積まで〜

黒田充紀，志澤一之

塑性と加工 Vol. 43 ( No. 495 ) 299-309 2002.04

Research paper (scientific journal), Joint Work

ポリマーの粘塑性大変形挙動に関する熱・力学的モデリングとシミュレーション (第1報，ひずみ速度依存性に由来する構成式の非共軸性)

村上大介, 小林誠一, 鳥垣俊和, 志澤一之

日本機械学会論文集A編 Vol. 68 ( No. 668 ) 674-681 2002.04

Research paper (conference, symposium, etc.), Joint Work

ポリマーの粘塑性大変形挙動に関する熱・力学的モデリングとシミュレーション (第2報，流れ則に基づく尖り点モデルとそのFEM解析)

村上大介, 小林誠一, 鳥垣 俊和, 志澤一之

日本機械学会論文集 A編 Vol. 68 ( No. 668 ) 682-689 2002.04

Research paper (conference, symposium, etc.), Joint Work

A Thermodynamic Theory of Plasticity based on Dislocation Density and Incompatibility Tensors

志澤一之，菊池完人，H. M. Zbib

Mater. Sci. Eng Vol. A309 ( No.310 ) 416-419 2001.07

Research paper (conference, symposium, etc.), Joint Work

A Self-Organization Model and Simulation of Collective Dislocations Based on Interaction between GN Dislocation and Dislocation Dipole

森田洋平，志澤一之，H. M. Zbib

Mater. Sci. Res. Int., Spec. Tech. Publ Vol.2   323-326 2001.05

Research paper (conference, symposium, etc.), Joint Work

A Strain Rate Hardening Rule for Polymeric Materals and FEM Analysis of Viscoplastic Large Deformation

村上大介，小林誠一，鳥垣 俊和，志澤一之

Proceedings of 37th Annual Technical Meeting Society of Engineering Science    II-256. 2000.10

Research paper (conference, symposium, etc.), Joint Work

転位ドリフト速度理論における塑性スピンと背応力の構成式に対する熱・力学的検討

志澤一之，若林宏樹

日本機械学会論文集, A編 Vol.66 ( No.647 ) 1290-1296 2000.07

Research paper (conference, symposium, etc.), Joint Work

　View Summary

著者らが提案した転位ドリフト速度理論に非Riemann塑性論的考察を加え，塑性スピンに共役な内力の存在を提唱するとともに，塑性スピンと背応力の構成式を熱力学的手法によって新たに導出し，転位運動に立脚した移動硬化塑性体モデルを構築した．

原子の配列状態を示す指標の導入とそれを用いた固体の弾性定数テンソルの微視的表現

安井義博，星野　豊，志澤一之，高橋邦弘

日本機械学会論文集, A編 Vol.66 ( No.641 ) 7-13 2000.01

Research paper (conference, symposium, etc.), Joint Work

　View Summary

固体を構成する原子集団の配列状態を表現するPテンソルなる指標を新たに定義し，原子の運動方程式をメゾ領域内で平均化することにより，固体の弾性定数テンソルを理論的に予測する方法を提案した．

Microscopic Discussions of Macroscopic Balance Equations for Solids Based on Atomic Configuretions

中根一起，志澤一之，高橋邦弘

Arch. Appl. Mech. Vol.70   533-549 2000

Research paper (conference, symposium, etc.), Joint Work

　View Summary

固体を原子の集合体としてモデル化する際，メゾ要素内における諸量のこう配と巨視的こう配が異なる場合について，諸保存則ならびに諸内力の微視的表現をMicromorphic理論に基づいて定式化した．また，得られた微視的表現の妥当性を分子動力学シミュレーションによって検証した．

A thermodynamical theory of gradient elastoplasticity with dislocation density tensor. I: Fundamentals

志澤一之，H. M. Zbib

Int. J. Plasticity Vol.15 ( No.9 ) 899-938 1999.09

Research paper (conference, symposium, etc.), Joint Work

　View Summary

転位運動を考慮した有限変形塑性論を構築するため，GN転位密度を自由エネルギーの引数に導入し，塑性変形速度，背応力，塑性スピンおよび転位ドリフト速度に対する構成式を転位運動と関連づけて熱力学的に導出する手法を提案した．

A Thermodynamical Theory of Plastic Spin and Internal Stress with Dislocation Density Tensor

Trans. ASME J. Engng. Mater. Tech Vol.121 ( No.2 ) 247-253 1999.04

Research paper (conference, symposium, etc.), Joint Work

Equivalence between Higher-Order Stress Power and Heat Flux in Energy Equation based on Lattice Dynamics

Trans. ASME J. Engng. Mater. Tech Vol.121 ( No.2 ) 240-246 1999.04

Research paper (conference, symposium, etc.), Joint Work

Diffusion Equations Based on Generalized Continuum Mechanics

横塚剛秀，船迫匠，島田英徳，志澤一之，高橋邦弘

Heat Transfer Japanese Research Vol. 62 ( No.2 ) 84-96 1997.12

Research paper (conference, symposium, etc.), Joint Work

　View Summary

エントロピーの増大に必要なメゾ領域を考えて，拡散現象に非局所性を導入する場合，拡散方程式は濃度と微視的濃度こう配に対する連立偏微分方程式になることを1次元理論に基づいて示した。また，本方程式系を非定常境界値問題に適用して数値解析を行い，本理論が無限伝播速度の問題に対して一つの解決策を与え得ることを明らかにした。

金属材料における原子配列を考慮した応力および高次応力の微視的表現

安井義博，安井健真，志澤一之，高橋邦弘

材料 Vol.46 ( No.12 ) 1355-1361 1997.12

Research paper (conference, symposium, etc.), Joint Work

　View Summary

原子運動をメゾ要素内で平均化することによって得た高次応力の微視的表現を用いて分子シミュレーションの結果を整理し，従来の高次応力に対する巨視的定義式から計算される結果と比較検討することにより，本微視的表現の妥当性を明らかにした。

固体内部の原子配列を考慮した極性体モデルにおける巨視的な応力の一般化された表現と諸釣合い方程式

中根一起、志澤一之、高橋邦弘

日本機械学会論文集、A編 Vol.63 ( No.612 ) 1694-1700 1997.08

Research paper (conference, symposium, etc.), Joint Work

　View Summary

単純立方格子に対して著者らが微視的に検討してきたMicromorphic体モデルを，原子配列がランダムな場合に拡張し，その諸釣合い方程式を一般化することを試みた。

Thermomechanical derivation of Noncoaxial Plastic Constitutive equations Considering Spins of Objective Stress Rates

志澤一之

JSME International Journal，Series A Vol.40 ( No.3 ) 336-342 1997.07

Research paper (conference, symposium, etc.), Single Work

　View Summary

共回転応力速度におけるスピンを与える中間配置が満足すべき熱力学的要請を明らかにした。また，最大エントロピー生成速度の原理に立脚した熱力学的体系のもとで，散逸関数を塑性ポテンシャルとする流れ則の形で非共軸塑性構成式を導出する手法を構築した。

原子配列を考慮した極性体モデルに対するエネルギー方程式

中根一起,藤沼宏之,澤一之,橋邦弘

日本機械学会論文集、A編 Vol.63 ( No.609 ) 1104-1111 1997.05

Research paper (conference, symposium, etc.), Joint Work

　View Summary

原子運動を基礎としてMicromorphic体のエネルギー方程式を導出し，熱流束や内部エネルギーを原子間ポテンシャルや原子配列のファブリックベクトル等を用いて微視的に表現した。また，熱流束と高次応力の等価性に加え，内部エネルギーと慣性スピン仕事率との等価性についても明らかにした。

原子配列を考慮した極性体モデルに対する力学的釣合い方程式

中根一起、藤沼宏之、志澤一之、高橋邦弘

日本機械学会論文集、A編 Vol.63 ( No.609 ) 1096-1103 1997.05

Research paper (conference, symposium, etc.), Joint Work

　View Summary

変形の微視的こう配と巨視的こう配が異なることを前提としてモデル化されたMicromorphic極性体の力学的釣合い方程式を原子運動に基づいて微視的に導出し，Micromorphic体に特有な高次応力を面積平均値として微視的に定式化した。

原子配列を考慮したエネルギー方程式における高次応力仕事率と熱流束の等価性

安井義博、志澤一之、高橋邦弘

日本機械学会論文集，A編 Vol.63 ( No.607 ) 595-602 1997.03

Research paper (conference, symposium, etc.), Joint Work

　View Summary

原子レベルの微視的考察から導出した高次応力と熱流束の定義式を比較検討することにより，高次物質における高次応力仕事率が単純体の熱流束の一部であることを明らかにし，両者の等価性について論じた。

原子配列を考慮したエネルギー方程式の微視的導出手法

安井義博、志澤一之、高橋邦弘

日本機械学会論文集，A編 Vol.62 ( No.601 ) 2116-2121 1996.09

Research paper (conference, symposium, etc.), Joint Work

　View Summary

固体内部の原子集団の挙動をメゾ要素内で平均化することにより，高次応力，熱流束，内部エネルギーなどの微視的表現を与えると同時に，エネルギー方程式を微視的に導出した。

客観応力速度のスピンを考慮した非共軸形塑性構成式に対する熱力学的導出手法

志澤一之

日本機械学会論文集，A編 Vol.62 ( No.599 ) 1649-1655 1996.07

Research paper (conference, symposium, etc.), Single Work

　View Summary

客観応力速度における共回転スピンが満足すべき熱力学的要請を明らかにすると同時に，最大エントロピー生成速度の原理に立脚した熱力学的体系のもとで，散逸関数を塑性ポテンシャルとする流れ則の形で非共軸塑性構成式を導出する手法を構築した。

非局所性を考慮した金属内の拡散における基礎方程式

横塚剛秀、志澤一之、高橋邦弘

日本機械学会論文集，A編 Vol.62 ( No.599 ) 1590-1596 1996.07

Research paper (conference, symposium, etc.), Joint Work

　View Summary

物体内にメゾ要素を考え，それを金属中の結晶粒に対応させることにより，材料の内部構造を考慮した拡散理論を一般化連続体力学的に構築した。

設計・製図教育の変遷

徳岡直静，青山英樹，志澤一之

設計工学 Vol.31 ( No.6 ) 10-13 1996.06

Research paper (scientific journal), Joint Work

　View Summary

今後の理工系大学においては，設計教育と加工教育を融合した総合的実習科目の創設が不可欠であることを論じ，計算機支援によるCAD，CAM，CAT一連の体験実習の必要性について述べた。

一般化連続体力学を用いた拡散方程式の導出とその数値解析

横塚剛秀、船迫匠、島田英徳、志澤一之、高橋邦弘

日本機械学会論文集，B編 Vol.62 ( No.597 ) 1977-1983 1996.05

Research paper (conference, symposium, etc.), Joint Work

　View Summary

エントロピーの増大に必要なメゾ領域を考えて，拡散現象に非局所性を導入する場合，拡散方程式は濃度と微視的濃度こう配を未知量とする連立偏微分方程式になることを示した。また，本方程式系が無限伝播速度の問題に対して一つの解決策を与え得ることを数値解析的に明らかにした。

Discussion of Thermomechnics on the Basis of Frame Invariance of Physical Law

JSME Int.J Vol.37 ( No.1 ) 7-13 1994.01

Research paper (conference, symposium, etc.), Single Work

　View Summary

互いに剛体運動する2人の観測者に対して熱力学の第1・第2法則が不変であることを利用して，力学的保存則および構成量に対する標構変換則を同時に得るというエネルギー手法を提案した。また標構無差別性原理と一般相対性原理の関係について調べ，前者の位置づけを明確にした。

非瞬時性を考慮した連続体に対する基礎方程式系

小林誠一，志澤一之，高橋邦弘

日本機械学会論文集（A編） Vol.59 ( No.568 ) 2885-2892 1993.12

Research paper (conference, symposium, etc.), Joint Work

　View Summary

熱力学的諸量に非瞬時性を導入した場合の連続体に対する基礎方程式系を導出し，熱弾性体に対する運動方程式には温度速度応力に起因する項が生じ，熱伝導方程式と新たな連成を生じること，ならびに熱伝導方程式が双曲型に変更され，温度の無限伝播速度の問題を回避できることを明らかにした。

微視的温度曲率を考慮した連続体の基礎方程式系

小林誠一，志澤一之，高橋邦弘

日本機械学会論文集（A編） Vol.59 ( No.559 ) 868-875 1993.03

Research paper (conference, symposium, etc.), Joint Work

　View Summary

微視的温度曲率を考慮した連続体に対する諸構成式ならびに基礎方程式系を導出し，非平衡性の強い熱伝導現象を扱う際には温度や温度こう配のみならず温度曲率の影響をも考慮する必要があることを指摘した。

微視的温度曲率を考慮した連続体の熱力学的考察

小林誠一，志澤一之，高橋邦弘

日本機械学会論文集（A編） Vol.59 ( No.557 ) 232-239 1993.01

Research paper (conference, symposium, etc.), Joint Work

　View Summary

物質の状態が空間的に激しく変動する非平衡過程を扱うために，物質中にメゾ要素を考え，その領域中の2次のゆらぎ（微視的温度曲率）までを考慮した場合の連続体に対し，その構成式に熱力学的検討を加えた。

非瞬時性を考慮した連続体に対する熱力学的考察

小林誠一，志澤一之，高橋邦弘

日本機械学会論文集（A編） Vol.59 ( No.557 ) 225-231 1993.01

Research paper (conference, symposium, etc.), Joint Work

　View Summary

時間的に激しく変動する連続体の非平衡過程を表現するために，熱力学的諸量に非瞬時性を導入した。その結果，エントロピー流束ならびに保存応力の構成式に温度速度に依存する項が付加されることを示した。

薄肉開き断面部材の断面変形に関する実験的検討

志澤一之，高橋邦弘

土木学会論文集  ( No.450/I-20 ) 193-196 1992.07

Research paper (conference, symposium, etc.), Joint Work

　View Summary

薄肉開き断面部材に断面変形現象が実際に生ずることを実験的に検証し，設計において部材剛性を安全側に見積るためには断面変形を考慮する必要があることを明らかにした。

標構無差別性原理の立場に関する熱力学的考察

日本機械学会論文集（A編） Vol.58 ( No.550 ) 880-886 1992.06

Research paper (conference, symposium, etc.), Single Work

　View Summary

熱力学の第1・第2法則の客観性を認めることで，応力等の構成式に対する標構変換則が導けることを示し，標構無差別性原理が一般相対性原理に包含されていることなどについて議論した。

微視的温度こう配を考慮した熱極性物質の基礎方程式系

小林誠一，志澤一之，高橋邦弘

日本機械学会論文集（A編） Vol.58 ( No.549 ) 725-730 1992.05

Research paper (conference, symposium, etc.), Joint Work

　View Summary

微視的温度こう配を考慮した熱極性物質に対する運動方程式，熱伝導方程式および温度のゆらぎに対する方程式を導出するとともに，本方程式系に現れる新たな物質定数が満足すべき関係式を導いた。

微視的温度こう配を考慮した熱極性物質の構成式

小林誠一，志澤一之，高橋邦弘

日本機械学会論文集（A編） Vol.58 ( No.548 ) 607-613 1992.04

Research paper (conference, symposium, etc.), Joint Work

　View Summary

連続体中にメゾ要素を考え，その中で定義される微視的温度こう配が熱的ゆらぎを支配するような熱極性物質に対する構成式を熱力学的制約条件が満足されるように導出し，応力が微視的温度こう配にも依存することを明らかにした。

高階層極性物質の連続体力学（第4報・構成式に対する熱力学的考察）

志澤一之，小林誠一，高橋邦弘

日本機械学会論文集（A編） Vol.57 ( No.536 ) 900-906 1991.04

Research paper (conference, symposium, etc.), Joint Work

　View Summary

高階層極性物質に対するClausius-Duhemの不等式を導くことにより，諸内力と自由エネルギー・散逸関数との間に成立する関係式を導出し，内力の諸構成式が満足すべき熱力学的制限を明らかにした。

高階層極性物質の連続体力学（第3報・ひずみおよび変位）

志澤一之，小林誠一，高橋邦弘

日本機械学会論文集（A編） Vol.57 ( No.536 ) 892-899 1991.04

Research paper (conference, symposium, etc.), Joint Work

　View Summary

高階層極性物質の変形を特徴づける独特のひずみおよび変位を新たに定義し，さらに，ひずみ-変位関係式を与えることにより，ここで定義したひずみの幾何学的意味について考察した。

高階層極性物質の連続体力学（第2報・力学的釣合い方程式およびバイモーメントの概念の拡張）

志澤一之，高橋邦弘

日本機械学会論文集（A編） Vol.55 ( No.519 ) 2363-2369 1989.11

Research paper (conference, symposium, etc.), Joint Work

　View Summary

高階層極性体に対する力学的釣合い方程式を導出して，双偶応力なる新たな内力を定義し，それが薄肉構造部材におけるバイオモーメントを一般化した内力であることを指摘した。

高階層極性物質の連続体力学（第1報・運動学）

高橋邦弘，志澤一之

日本機械学会論文集（A編） Vol.55 ( No.519 ) 2356-2362 1989.11

Research paper (conference, symposium, etc.), Joint Work

　View Summary

著者の一人が提唱した高階層極性体の概念に基づいて，その運動学に対して定式化を行い，階層2の極性体は従来の極性体が有する変位，回転の自由度に加え，ねじれ回転の自由度をも有することを明らかにした。

Theoretical Consideration of the Fundamental Behavior of Conducting Magnetic Fluids（1st Report，Couette Like Flow）

金田武司，志澤一之，棚橋隆彦

JSME International Journal Vol.30 ( No.268 ) 1567-1576 1987.10

Research paper (conference, symposium, etc.), Joint Work

　View Summary

平行平板間導電性磁性流体のクェット的流れに対する流れ場，電磁場および温度場などの解析解を求めた。また，流れを特徴づける新たな数個の無次元数を定義し，それらが流れに及ぼす影響について検討した。

導電性磁性流体の基本的流動特性に関する理論解析（平行平板間単純せん断流れ）

志澤一之，井門康司，棚橋隆彦

日本機械学会論文集（B編） Vol.53 ( No.492 ) 2423-2432 1987.08

Research paper (conference, symposium, etc.), Joint Work

　View Summary

導電性磁性流体の平行平板間単純せん断流れに対して理論解析を行い，主な流体力学的諸量の解析解を求めた。また，流れ場と電磁場の相互作用を表す無次元数が，流れに及ぼす影響について議論した。

磁性流体の基本的流動特性に関する理論解析（単純せん断流れと一定圧力勾配流れの比較）

志澤一之，井門康司，棚橋隆彦

日本機械学会論文集（B編） Vol.53 ( No.492 ) 2404-2413 1987.08

Research paper (conference, symposium, etc.), Joint Work

　View Summary

平行平板間における磁性流体の単純せん断流れと一定圧力勾配流れについて理論解析を行い主な流体力学的諸量の解析解を求めた。また，流れを特徴づける数個の無次元数が2種の流れに及ぼす影響の相違について調べた。

磁性流体のキャビティ内流れの数値解析（磁性流体のGSMAC有限要素法解析）

岡永博夫，志澤一之，八嶋 昇，棚橋隆彦

日本機械学会論文集（B編） Vol.53 ( No.492 ) 2414-2422 1987.08

Research paper (conference, symposium, etc.), Joint Work

　View Summary

磁性流体の2次元汎用流動解析アルゴリズムであるGSMAC有限要素法を提案した。これを用いて正方形キャビティ内における磁性流体の強制対流問題について数値解析を行い，磁場が渦中心の位置に及ぼす影響について考察した。

磁性流体の円管内助走区間領域の流動解析

御林 毅，志澤一之，棚橋隆彦，清水治和

日本機械学会論文集（B編） Vol.53 ( No.491 ) 2027-2036 1987.07

Research paper (conference, symposium, etc.), Joint Work

　View Summary

入口速度分布が一様な場合および放物形の場合の円管内磁性流体の助走区間問題について数値解析を行い，印加磁場が流れの発達に及ぼす影響について議論した。

導電性磁性流体の基礎的挙動に関する理論的考察（第1報・クェット的流れ）

金田武司，志澤一之，棚橋隆彦

日本機械学会論文集（B編） Vol.52 ( No.487 ) 865-874 1987.03

Research paper (conference, symposium, etc.), Joint Work

　View Summary

平行平板間導電性磁性流体のクェット的流れに対する流れ場，電磁場および温度場などの解析解を求めた。また，流れを特徴づける新たな数個の無次元数を定義し，それらが流れに及ぼす影響について検討した。

A New Complete Set of Basic Equations for Conducting Magnetic Fluids with Internal Rotation（Derivation by Thermodynamical Method）

志澤一之，棚橋隆彦

Journal of Magnetism and Magnetic Materials Vol.65 ( No.2&3 ) 181-184 1987.02

Research paper (conference, symposium, etc.), Joint Work

　View Summary

自由エネルギーと散逸関数が諸構成式の支配関数であることを利用して，内部自由度を有する導電性磁性流体の基礎方程式系を，エネルギー方程式を含めて導出した。

New Constitutive Equations for Conducting Magnetic Fluids with Internal Rotation（Thermodynamical Discussions）

志澤一之，棚橋隆彦

Bulletin of the JSME Vol.29 ( No.255 ) 2878-2884 1986.09

Research paper (conference, symposium, etc.), Joint Work

　View Summary

内部回転を考慮した導電性磁性流体の構成式を熱力学的手法によって初めて導出した。その際，物理的不備を有する磁化の緩和方程式を排除し，新たに磁化の構成式を熱力学の第2法則を常に満足するように決定した。

粘弾性効果を考慮した磁性流体の構成方程式に対する熱力学的考察（極性流体理論）

志澤一之，棚橋隆彦

日本機械学会論文集（B編） Vol.52 ( No.480 ) 2905-2912 1986.08

Research paper (conference, symposium, etc.), Joint Work

　View Summary

磁性流体のもつ粘弾性効果を構成式に導入することにより，磁性流体の応力の構成式がネマティック状態にある液晶のそれと等価となることを連続体力学的に示した。

Thermodynamical Discussions for the Basic Equations of Conducting Magnetic Fluids（Nonrelativistic and Nonpolar Theory）

志澤一之，棚橋隆彦

Bulletin of the JSME Vol.29 ( No.250 ) 1171-1176 1986.04

Research paper (conference, symposium, etc.), Joint Work

　View Summary

導電性磁性流体の基礎方程式を定式化する準備段階として，電磁場と流れ場の相互作用を厳密に取り扱うことに重点を置き，磁性流体を一様等方性流体とみなしてその方程式系を熱力学的手法によって導出した。

Distorted Pressure Histories due to the Step Responses in a Linear Tapered Pipe （6th Report，For Arbitrary Cross-Sections）

棚橋隆彦，澤田達男，志澤一之，安藤常世

Bulletin of the JSME Vol.29 ( No.249 ) 795-801 1986.03

Research paper (conference, symposium, etc.), Joint Work

　View Summary

ラプラス変換法を用いて，任意形状の管断面をもつ直線テーパ管のステップ応答に対する理論解析を行い，その波動現象について調べた。さらに，同モデルに対して実験を行い両者の結果を比較・検討した。

内部回転を考慮した導電性磁性流体の基礎方程式（熱力学的手法による誘導）

志澤一之，棚橋隆彦

日本機械学会論文集（B編） Vol.52 ( No.473 ) 325-333 1986.01

Research paper (conference, symposium, etc.), Joint Work

　View Summary

内部回転を考慮した導電性磁性流体の構成式を熱力学的手法によって初めて導出した。その際，物理的不備を有する磁化の緩和方程式を排除し，新たに磁化の構成式を熱力学の第2法則を常に満足するように決定した。

A New Complete Set of Basic Equations for Magnetic Fluids with Internal Rotation（Derivation by Themodynamical Method）

志澤一之，棚橋隆彦

Bulletin of the JSME Vol.28 ( No.243 ) 1942-1948 1985.09

Research paper (conference, symposium, etc.), Joint Work

　View Summary

Shliomisが提唱した磁性流体の基礎方程式に内在する理論的不備を指摘し，熱力学的手法を用いて応力の保存部分および偶応力の構成式に対して改良を加え，物理的により妥当な形に修正した。

導電性磁性流体の基礎方程式に対する熱力学的考察（非相対性・非極性理論）

志澤一之，棚橋隆彦

日本機械学会論文集（B編） Vol.51 ( No.468 ) 2737-2745 1985.08

Research paper (conference, symposium, etc.), Joint Work

　View Summary

導電性磁性流体の基礎方程式を定式化する準備段階として，電磁場と流れ場の相互作用を厳密に取り扱うことに重点を置き，磁性流体を一様等方性流体とみなしてその方程式系を熱力学的手法によって導出した。

直線テーパ管内のステップ応答と圧力波形について（第6報・管断面形状が任意の場合）

棚橋隆彦，澤田達男，志澤一之，安藤常世

日本機械学会論文集（B編） Vol.51 ( No.467 ) 2313-2320 1985.07

Research paper (conference, symposium, etc.), Joint Work

　View Summary

ラプラス変換法を用いて，任意形状の管断面をもつ直線テーパ管のステップ応答に対する理論解析を行い，その波動現象について調べた。さらに，同モデルに対して実験を行い両者の結果を比較・検討した。

内部回転を考慮した磁性流体の新しい基礎方程式（熱力学的手法による誘導）

志澤一之，棚橋隆彦

日本機械学会論文集（B編） Vol.51 ( No.461 ) 95-105 1985.01

Research paper (conference, symposium, etc.), Joint Work

　View Summary

Shliomisが提唱した磁性流体の基礎方程式に内在する理論的不備を指摘し，熱力学的手法を用いて応力の保存部分および偶応力の構成式に対して改良を加え，物理的により妥当な形に修正した。

Response of Magnetic Fluids in Annular Pipes under the Influence of External Magnetic Fields

上記に同じ。

Bulletin of the JSME Vol.27 ( No.229 ) 1431-1437 1984.07

Research paper (conference, symposium, etc.), Joint Work

　View Summary

磁場を任意の方向に印加した場合の磁性流体の二重円管内流れに関し理論解析を行い，主な流体力学的諸量の外部磁場に対する応答を調べた。

二重円管内の磁性流体の外部磁場に対する磁気的応答

棚橋隆彦，澤田達男，志澤一之，安藤常世

日本機械学会論文集（B編） Vol.49 ( No.447 ) 2513-2521 1983.11

Research paper (conference, symposium, etc.), Joint Work

　View Summary

磁場を任意の方向に印加した場合の磁性流体の二重円管内流れに関し理論解析を行い，主な流体力学的諸量の外部磁場に対する応答を調べた。