Evaluating and modeling the behaviour of 2-D braided composites for cardiovascular catheter development

几十年来，二维和三维编织复合材料一直被用作结构增强材料。近年来，二维编织复合材料已被研究用于非传统应用的新用途，如特征直径从0.8 mm到4 mm的导管，以及在其长度上具有不同形状和紧曲率区域的运动器材。我的研究计划的长期目标是研究、更好地理解和预测基于开放和闭合网状纤维的二维编织复合材料层压板的性能，这些结构可以是刚性的，也可以是柔性的。短期目标是四个项目，它们都满足了来自长期和中期目标的挑战：(1)通过改进编织-芯棒复盖率优化的运动学模型，发展在复杂形状的芯棒上编织的能力。(2)研制一套完整的结构应变测量工具。(3)分析了刚性和柔性聚合物基管状编织材料在小变形到大变形下的准静态加载弹性行为，并对实验结果进行了分析。由于复杂的非线性行为和依赖于变形的弹性性能，对导管至关重要的柔性矩阵的使用是具有挑战性的。(4)研究了链路径和截面对预测模型的影响。该研究计划预计将对编织复合材料的基本理论和行为理解产生重大影响。它将建立一个不同形状和大小的编织复合材料的实验数据的大型数据库，以充分评估它们的性能和用途。研究结果将适用于以其他方式制造的复合材料和其他单胞结构。这项工作将继续对医疗导管技术产生影响，该技术已经确定了2D开放网状编织可以满足的设计弱点。改进的导管技术对患者的生活质量、节省时间和改善医生的操作程序的影响是显而易见的。六名博士、两名硕士和五名本科生将在这项研究计划中接受培训，他们非常受加拿大劳动力的欢迎。

Two- and three- dimensional braided composites have been used for decades as structural reinforcements. In recent years, 2-D braided composites have been studied for novel use in unconventional applications, such as catheters, which have characteristic diameters ranging from 0.8 mm to 4 mm, and sports equipment, which has varying shapes and regions of tight curvature over their lengths. Long term objectives of my research program are to study, understand better and predict the behaviour of open- and closed-mesh fibre-based two-dimensional braided composite laminate-based structures produced with either rigid or flexible resin matrices. Short term objectives are four projects which all meet challenges deriving from long and medium term objectives: (1) Develop the capability to braid over complex-shaped mandrels by improving kinematic models for braid-mandrel coverage optimization. (2) Develop a tool to perform full structure strain measurements. (3) Analyse experimental results and develop models for the elastic behaviour of rigid- and flexible-polymer matrix tubular braids under small to large deformation, in quasi-static loading. The use of flexible matrices, critical to catheters, is challenging because of complex non-linear behaviours and deformation- dependent elastic properties. (4) Investigate strand path and cross section effects on predictive models. The research program is anticipated to have a significant impact on fundamental braided composite materials theory and behavioural understanding. It will produce a large database of experimental data of braided composite with varying shapes and size to assess fully their behaviour and usefulness.The findings will be applicable to composite materials manufactured by other means and other unit cell configurations. This work will continue to have an impact on medical catheter technology, which has identified design weaknesses that can be met by 2D open mesh braiding. The effect of improved catheter technology on patient quality of life, for saving time, and improving the procedure for medical doctors is palpable. Six PhDs, two MSc and five undergraduate students, highly desirable to the Canadian work force, will be trained in this research program.