2015 Fiscal Year Final Research Report
Unified modeling of size effects in mechanical properties of metals
| Project/Area Number |
25289001
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Partial Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Yamagata University |
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Principal Investigator |
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| Research Collaborator |
KOIZUMI Takayuki
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 構成式 / 結晶塑性 / サイズ効果 |
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| Outline of Final Research Achievements |
The higher-order gradient crystal plasticity (HOGCP) model that was proposed by the principal investigator has a potential capability to represent a wide range of size effects observed in mechanical properties of metals. However, methodology for modeling of interfaces (i.e. grain boundaries in polycrystals) has not yet been established. Thus, the HOGCP model could not represent the mechanical behavior of polycrystals precisely. In the present study, a new grain boundary model is proposed. In the model, it is assumed that yielding of grain boundaries occurs when the dislocation density at the grain boundary, which increases due to dislocation pileups, reaches a critical value. To confirm the validity of the model and to identify the material parameters included in the model, an experimental study using an ultra-fine grain metal (Al) was conducted. The experimental results suggested that the grain boundaries in the material did not act as strong barriers to dislocation motion.
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| Free Research Field |
塑性力学，計算力学
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