| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Research Abstract |
In this research, to develop a micro-stent for carotid artery, a method for structural analysis of finite element method (FEM) was discussed considering the deformation characteristic and microstructural change of the constituent materials of the stent such as SUS316L and pure titanium. As a result, the following conclusions were obtained:
1)Clarification of basic characteristic of deformation of the constituent materials
i)Effect of predeformation on the deformation characteristic: The effect of the loading direction on the subsequent deformation was clarified using the materials of commercially pure (CP) titanium and SUS316L stainless steel.
ii)Clarification of viscoplastic deformation: The strain rate effect on the stress-strain relations caused by the pure tensile tests was clarified using CP-Titanium and SUS316L stainless steel. The creep characteristics of the materials were also clarified.
2)Clarification of the relationship between deformation and surface aspect
i)Observation on the surface aspect: Using the rectangular specimens, the pure tensile tests with several strain rate, creep test, stress relaxation test, and strain relaxation test were conducted. The surface of the specimens was observed and the surface aspects were correlated with the deformation. In the case of CP-titanium, the surface aspect due to the pure tensile deformation is different from that due to the creep deformation, while, in the case of SUS316L stainless steel, the surface aspect due to the pure tensile deformation is as same as that due to the pure creep deformation.
3)FEM analysis of the deformation of the stent
i)Expansion analysis: The deformation of the edge of the stent can be controlled by changing the structure of mesh of stent.
ii)FEM analysis considering the repeated structure of stent: The repeated unit cell (RUC) model was proposed to analyze the deformation of the stent effectively.
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