2000 Fiscal Year Final Research Report Summary
Mesoscopic simulation of dislocations and observation of dislocation structure
| Project/Area Number |
11650687
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical properties of metals
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| Research Institution | Meiji University |
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Principal Investigator |
KOIZUMI Hirokazu Meiji University, Department of Physics, Professor, 理工学部, 教授 (60126050)
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| Project Period (FY) |
1999 – 2000
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| Keywords | dislocation / mesoscopic / simulation / dislocation segment / elastic interaction / radiation loss / lattice vibration / Peierls potential |
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| Research Abstract |
In order to understand the plasticity of solids it is important to describe the motion of many dislocations. This problem is not so easy, because a dislocation bends and the interaction between dislocations is long-range. To investigate the motion of dislocations, dislocation are divided into short straight segments and the equations of motion for the nodes (junctions of two segments) are obtained. Long-range elastic interaction is included.Viscous force, which is proportional to the velocity, is assumed to act on the dislocations. Computer simulation of the Frank-Read source of dislocations was performed as an example.
In real crystals a dislocation accelerates and decelerates due to the lattice periodicity, or the Peierls potential. The dislocation emits lattice waves and loses kinetic energy. Therefore, the lattice waves should be included as an interaction, and a term expressing the radiation loss should be included. The first is not so important at moderate temperatures, but the second cannot be ignored. Simulations on the radiation of lattice waves from a moving dislocation were also performed. The radiation loss cannot be described simply by a term proportional to the velocity.
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