Abstract We present the results of a computational study aimed at capturing the behavior over time of Dacron fabric used for surgical correction of aortic aneurysms. The study concerns the problem of compliance mismatch between the graft and the native aorta and is very important to clinicians. The aorta is represented by a sophisticated anisotropic hyperelastic model (GOH), which takes into account the orientation of the collagen fibers. The corrugations present on the Dacron fabric are modeled geometrically using experimental data retrieved from the literature. The viscoelastic behavior of the Dacron graft reported by clinicians is also taken into account. Mechanical quantities experienced by the graft sewn to an aortic segment are obtained using fluid–structure interaction (FSI) simulations assuming realistic blood flow conditions. Both ascending and descending aorta with two curvatures are considered. Results of this study indicate that (i) the strains on the Dacron-aorta structure increase with increasing curvature and over time (ii) the simulations are capable of capturing stress concentrations at the junction of the graft and the aorta and (iii) the wall shear stresses (WSS) are substantially higher on the aortic segment than on the Dacron graft.

中文翻译：

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用于主动脉置换的各向异性涤纶织物的流固耦合分析

摘要 我们介绍了一项计算研究的结果，该研究旨在捕捉用于主动脉瘤手术矫正的涤纶织物随时间的变化。该研究涉及移植物和天然主动脉之间顺应性不匹配的问题，对临床医生非常重要。主动脉由复杂的各向异性超弹性模型 (GOH) 表示，该模型考虑了胶原纤维的方向。涤纶织物上的波纹是使用从文献中检索到的实验数据以几何方式建模的。临床医生报告的涤纶移植物的粘弹性行为也被考虑在内。缝合到主动脉段的移植物所经历的机械量是使用流体-结构相互作用 (FSI) 模拟获得的，假设真实的血流条件。具有两个曲率的升主动脉和降主动脉都被考虑。这项研究的结果表明 (i) 涤纶主动脉结构上的应变随着曲率和时间的增加而增加 (ii) 模拟能够捕捉移植物和主动脉连接处的应力集中以及 (iii) 壁主动脉段上的剪切应力 (WSS) 明显高于涤纶移植物。