Braided stents are self-expandable devices widely used in many different clinical applications. In-silico methods could be a useful tool to improve the design stage and preoperative planning; however, numerical modeling of braided structures is not trivial. The geometries are often challenging, and a parametric representation is not always easily achieved. Moreover, in the literature, different options have been proposed to handle the contact among the wires, but an extensive comparison of these modeling techniques is missing. In this work, both the geometry and contact issues are discussed. Firstly, an effective strategy based on parametric equations to draw complex braided geometries is illustrated and exploited to build three beam meshes resembling commercial devices. Secondly, three finite element simulations (bending, crimping and confined release) were carried out to compare simplified contact techniques involving connector elements with the more realistic but computationally expensive option based on the general contact algorithm, which has already been validated in the literature through comparisons with experimental results. Both local (stress distribution) and global quantities (forces/displacements) were analyzed. The results obtained using the connectors are significantly affected by wire interpenetrations and over-constraint. The percentage errors reached considerably high values, exceeding 100% in the confined release test and 50% in the remaining cases study. Moreover, the errors do not show uniform trends but vary according to the stent geometry, boundary conditions, connector type and investigated entity, suggesting that it is not possible to replace the use of the general contact algorithm with simplified approaches.

编织支架是可自扩展的设备，广泛用于许多不同的临床应用中。硅内方法可能是改善设计阶段和术前计划的有用工具；但是，编织结构的数值建模并非易事。几何形状通常具有挑战性，并且并不总是容易实现参数表示。而且，在文献中，已经提出了处理导线之间的接触的不同选择，但是缺少这些建模技术的广泛比较。在这项工作中，讨论了几何和接触问题。首先，说明并利用一种基于参数方程的有效策略来绘制复杂的编织几何形状，并将其用于构建类似于商用设备的三个波束网格。其次，进行了三个有限元模拟（弯曲，进行压接和限制释放），以比较涉及连接器元件的简化接触技术与基于通用接触算法的更现实但计算成本更高的选择，该方法已在文献中通过与实验结果的比较得到了验证。分析了本地（应力分布）和全球数量（力/位移）。使用连接器获得的结果受电线互穿和过度约束的影响很大。百分比误差达到相当高的值，在密闭释放测试中超过100％，在其余案例研究中超过50％。此外，误差不会显示出统一的趋势，而是会根据支架的几何形状，边界条件，连接器类型和所研究的实体而有所不同，