Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, 8092 Zurich, Switzerland.
Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, 8092 Zurich, Switzerland.
J Mech Behav Biomed Mater. 2018 Jan;77:711-717. doi: 10.1016/j.jmbbm.2017.08.021. Epub 2017 Aug 24.
A systematic investigation of the factors affecting the suture retention test is performed. The specimen width w and the distance a of the suture bite from the specimen free edge emerge as the most influential geometrical parameters. A conservative approach for the quantification of suture retention strength is identified, based on the use of a camera to monitor the incipient failure and detect the instant of earliest crack propagation. The corresponding critical force, called break starting strength, is extremely robust against test parameter variations and its dependence on the specimen geometry becomes negligible when a≥ 2mm and w≥ 10mm. Comparison of suture retention and mode I crack opening tests reveals a linear correlation between break starting strength and tearing energy. This suggests that the defect created by the needle and the load applied by the suture thread lead to a fracture mechanics problem, which dominates the initiation of failure.
系统地研究了影响缝合线固位试验的因素。研究发现，缝线咬合处到试件自由边缘的距离 a 和试件宽度 w 是最具影响力的几何参数。基于使用相机监测初始失效并检测最早的裂纹扩展瞬间，确定了一种用于缝合线固位强度定量的保守方法。相应的临界力称为起始断裂强度，它对测试参数变化极其稳健，并且当 a≥2mm 和 w≥10mm 时，其对试件几何形状的依赖性可以忽略不计。缝合线固位和模式 I 裂纹张开试验的比较表明，起始断裂强度与撕裂能之间存在线性相关性。这表明，由针和缝线施加的负载引起的缺陷导致了断裂力学问题，从而主导了失效的开始。
