2018 Fiscal Year Final Research Report
Development of discrete dislocation plasticity analysis of BCC metals based on multiscale materials modeling
| Project/Area Number |
16K05044
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Computational science
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| Research Institution | Tokyo University of Science |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 転位動力学 / 分子動力学 / 転位 / モビリティ / スピノーダル分解 |
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| Outline of Final Research Achievements |
The crystal orientation and temperature dependence of dislocation velocity in BCC iron is investigated using an atomistic simulation method. The results illustrate the atomic dislocation core structure and its relationship with the dislocation velocity. The relationship is modeled to implement the information about the crystal orientation and temperature dependence of dislocation velocity into a dislocation dynamics simulation code. As a benchmark test of the developed method, a crystal model with a straight dislocation is prepared, and is subjected to a shear deformation. The resultant shear stress-strain relationship tells us that the method has a capability to account for the temperature dependence, which can be seen in BCC iron. The developed method is then applied to the numerical simulation of dislocation behavior in a spinodally decomposed Fe-Cr alloys. By the application, the relationship between the microstructure of the Fe-Cr alloy and the critical resolved shear stress.
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| Free Research Field |
材料力学，材料科学，材料強度学，計算力学
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| Academic Significance and Societal Importance of the Research Achievements |
本研究によって，金属中の格子欠陥である転位の特徴を分子動力学法による計算結果からモデル化し，そのモデルを直接転位動力学法に入力することによって，現実的な塑性変形解析が実現可能になることを示すことができた．具体的には，本研究の成果によって，BCC鉄の変形に見られる温度依存性を考慮することが可能になり，転位動力学法を用いたBCC鉄の塑性変形解析の信頼性を著しく向上させることに成功した．この成果により，今後析出物などの微視的組織と転位の相互作用に基づく材料の強化・劣化のより現実的なシミュレーションが可能となり，材料の信頼性評価や設計に対し大きく貢献することができる．
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