Abstract：The expansion and recoil of coronary stents under different balloon configurations were simulated to provide scientific guidance for the finite element simulation and optimization design of balloon expandable stents. The Cypher stent and four Raptor balloons (non-folded, tri-folded, six-folded and six-folded balloon with conical tip) were modeled by SolidWorks, the mesh generation was finished by Hypermesh, and the expansion and recoil of different balloon expandable stents were simulated by Abaqus Explicit. The simulation results were verified by the pressure-diameter compliance curve of the manufacturer. Besides, the maximum "dog-boning", foreshortening and radial recoil rates were depicted to evaluate different simulation effect. The non-folded balloon expandable stent expanded larger than others with low stress, and all three coefficients were the highest. Six-folded balloon expandable stent behaved well, its pressure-diameter compliance curve perfectly agreed with the manufacturer′s data than tri-folded configuration. Furthermore, its foreshortening (6.1%) and recoil (1.9%) rates were also lower than the former. As for the last one, its "dog-boning" (12%) and foreshortening (3.85%) rates were significantly lowest which may due to the conical tip. In the early stage of stent design, the non-folded configuration can be used to carry out the expansion and recoil simulation of the stent, but considering the transient behavior and the final positioning, the folded level and the conical tip design should be included in the simulation. From the point of optimization design, six-folded configuration is more beneficial to the uniform expansion of the stent than the tri-folded model.
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