Institute of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Oral Sciences, University of Otago, Dunedin, New Zealand.
Institute of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
J Mech Behav Biomed Mater. 2023 Feb;138:105617. doi: 10.1016/j.jmbbm.2022.105617. Epub 2022 Dec 10.
Despite of its assumed role to mitigate brain tissue response under dynamic loading conditions, the human dura mater is frequently neglected in computational and physical human head models. A reason for this is the lack of load-deformation data when the dura mater is loaded dynamically. To date, the biomechanical characterization of the human dura mater predominantly involved quasi-static testing setups. This study aimed to investigate the strain rate-dependent mechanical properties of the human dura mater comparing three different velocities of 0.3, 0.5 and 0.7 m/s. Samples were chosen in a perpendicular orientation to the visible main fiber direction on the samples' surface, which was mostly neglected in previous studies. The elastic modulus of dura mater significantly increased at higher velocities (5.16 [3.38; 7.27] MPa at 0.3 m/s versus 44.38 [35.30; 74.94] MPa at 0.7 m/s). Both the stretch at yield point λ (1.148 [1.137; 1.188] for 0.3 m/s, 1.062 [1.054; 1.066] for 0.5 m/s and 1.015 [1.012; 1.021] for 0.7 m/s) and stress at yield point σ of dura mater (519.14 [366.74; 707.99] kPa for 0.3 m/s versus 300.52 [245.31; 354.89] kPa at 0.7 m/s) significantly decreased with increasing velocities. Conclusively, increasing the load application velocity increases stiffness and decreases tensile strength as well as straining potential of human dura mater between 0.3 and 0.7 m/s. The elastic modulus of human dura mater should be adapted to the respective velocities in computational head impact simulations.
尽管硬脑膜被认为可以减轻动态加载条件下的脑组织反应，但在计算和物理人类头部模型中，硬脑膜经常被忽略。造成这种情况的一个原因是缺乏硬脑膜在动态加载下的变形数据。迄今为止，对硬脑膜的生物力学特性的研究主要涉及准静态测试设置。本研究旨在比较 0.3、0.5 和 0.7 m/s 三种不同速度，研究硬脑膜的应变率相关力学性能。样本取自与样本表面可见主纤维方向垂直的方向，这在以前的研究中大多被忽略。硬脑膜的弹性模量随速度的增加而显著增大（0.3 m/s 时为 5.16 [3.38；7.27] MPa，0.7 m/s 时为 44.38 [35.30；74.94] MPa）。屈服点应变 λ（0.3 m/s 时为 1.148 [1.137；1.188]，0.5 m/s 时为 1.062 [1.054；1.066]，0.7 m/s 时为 1.015 [1.012；1.021]）和屈服点应力 σ 也随速度的增加而显著降低（0.3 m/s 时为 519.14 [366.74；707.99] kPa，0.7 m/s 时为 300.52 [245.31；354.89] kPa）。总之，在 0.3 至 0.7 m/s 之间，增加加载速度会增加硬脑膜的刚度，降低拉伸强度和应变能力。在计算头部撞击模拟中，应根据相应的速度来调整硬脑膜的弹性模量。
