• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.1-6
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• 2017

Stents are widely used as the most common method of treating coronary artery disease with implants in the form of a metal mesh. The blood flow is normalized by inserting a stent into the narrowed or clogged areas of the human body. In this study, the mechanical characteristics of a stent are investigated according to the variations of its design parameters by the Taguchi method and finite element analysis. A stent model of the Palmaz-Schatz type was used for the analysis. In the analysis, an elasto-plastic material model was adopted for the stent and a hyper-elastic model was used for the balloon. The main interest of this study is to investigate the effects of the design parameters which reduce the possibility of restenosis by adjusting the recoil amount. A Taguchi orthogonal array was constructed on the model of the stent. The thickness and length and angle of the slot were selected as the design parameters. The amounts of radial recoil and longitudinal recoil were calculated by finite element analysis. The statistical analysis using the Taguchi method showed that optimizing the shape of the stent could reduce the possibility of restenosis. The optimized shape showed improvements of recoil in the radial and longitudinal directions of ~1% and ~0.1%, respectively, compared to the default model.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.869-876
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• 2011

It is important to analyze the dynamic behavior of counter-rotating rigid/deformable rolls in the roll-coating process, because the stability of the process is affected by the dynamic characteristics. In the present study, the effects of material property, angular velocity, and gap size on the contact pressure and contact shape of the deformable roll are numerically investigated. The behavior of two rolls with a negative gap was analyzed using the finite element method, and the material property of the deformable roll was applied with the Mooney-Rivlin coefficients of the hyper-elastic model. The contact shape is affected by the gap size, and the contact pressure mainly depends on the stiffness of the deformable roll and the gap size. To maintain a negative gap between two rolls, controls such as load and displacement controls must be used. The results indicate that displacement control can reduce the instability.