Sánchez-Molina David, García-Vilana Silvia, Llumà Jordi, Galtés Ignasi, Velázquez-Ameijide Juan, Rebollo-Soria Mari Carmen, Arregui-Dalmases Carlos
Escola d'Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain.
Institut de Medicina Legal i Ciències Forenses de Catalunya, G.V. Corts Catalanes, 111, 08014 Barcelona, Spain.
Biology (Basel). 2021 Aug 26;10(9):831. doi: 10.3390/biology10090831.
The mechanical properties of the cerebral bridging veins (CBVs) were studied using advanced microtensile equipment. Detailed high-quality curves were obtained at different strain rates, showing a clearly nonlinear stress-strain response. In addition, the tissue of the CBVs exhibits and a under cyclic loading, unequivocal indications of viscoelastic behavior. Interestingly, most previous literature that conducts uniaxial tensile tests had not found significant viscoelastic effects in CBVs, but the use of more sensitive tests allowed to observe the viscoelastic effects. For that reason, a careful mathematical analysis is presented, clarifying why in uniaxial tests with moderate strain rates, it is difficult to observe any viscoelastic effect. The analysis provides a theoretical explanation as to why many recent studies that investigated mechanical properties did not find a significant viscoelastic effect, even though in other circumstances, the CBV tissue would clearly exhibit viscoelastic behavior. Finally, this study provides reference values for the usual mechanical properties, as well as calculations of constitutive parameters for nonlinear elastic and viscoelastic models that would allow more accurate numerical simulation of CBVs in Finite Element-based computational models in future works.
使用先进的微拉伸设备研究了脑桥静脉（CBV）的力学性能。在不同应变率下获得了详细的高质量曲线，显示出明显的非线性应力-应变响应。此外，CBV组织在循环加载下表现出 和 ，这是粘弹性行为的明确迹象。有趣的是，大多数之前进行单轴拉伸试验的文献在CBV中未发现显著的粘弹性效应，但使用更灵敏的试验能够观察到粘弹性效应。因此，本文进行了仔细的数学分析，阐明了为何在中等应变率的单轴试验中难以观察到任何粘弹性效应。该分析为为何许多近期研究力学性能的研究未发现显著的粘弹性效应提供了理论解释，尽管在其他情况下，CBV组织会明显表现出粘弹性行为。最后，本研究提供了常规力学性能的参考值，以及非线性弹性和粘弹性模型的本构参数计算，这将有助于在未来的工作中基于有限元的计算模型对CBV进行更精确的数值模拟。
