| Project/Area Number |
14550070
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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 |
Materials/Mechanics of materials
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
KOGUCHI Hideo Nagaoka University of Technology, Department of Mechanical Engineering, Professor, 工学部, 教授 (90143693)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | Surface stresses / Molecular dynamics / Boundary condition / Boundary element analysis / Adhesion / Surface rigidy / Sensor / Nano machine |
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| Research Abstract |
We performed the study titled of 'New development and evaluation of stress analysis in nano-scale domain considering surface stresses' from 2002 to 2003. We performed several fundamental analyses on surface phenomena considering surface stresses. Finally, we could get the following results.
1.We could derive simple expressions for stresses and displacements in anisotropic materials where surface stresses vary in a step manner. Using this expressions, when As,Ge and so on cover the surface on Si, the bond length at Si surface varies, and then the variation of bond length could be evaluated. The variation of bond length was evaluated using the first principle calculation.
2.The adhesion contact analysis using the theory of elasticity was performed. The boundary condition considering the surface stresses, which are originated from surface energy. was employed for the surfaces of indenter and substrate. Furthermore, it was supposed the surface stresses in an adhesion region are different fro
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m that in a non-adhesion region and are reduced from the original surface stresses. A paraboloidal indenter is pressed into the substrate and adhesion occurs between two surfaces of the indenter and the substrate. The surfaces at the adhesion regions of the indenter and the substrate deformed inward due to the variation of the surface stresses. This means that the attractive force between the adhesion region occurs for maintaining the contact of the regions and the pull-off force of the indenter from the substrate is needed. The distribution of contact pressure, the surface profile of adhesion region and adhesive force between the indenter and the substrate were precisely examined. The results in the analysis were compared with those in the Hertz theory. The total force between the indenter and the substrate was about the value of 0.04 to 0.06 reduced from the dimensionless contact load based on Hertz theory.
3.Surface Green function considering surface stresses is derived using the theory of elasticity. Furthermore, a surface dipole Green function was derived, and the displacements at the surface atoms deduced from the theory were compared with those from MD. The theory considering surface stresses is useful in a nano scale domain. Less
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