Center for Applied Biomechanics, Department of Mechanical and Aerospace Engineering, University of Virginia, 4040 Lewis and Clark Dr., Charlottesville, VA, 229011, USA.
Biomechanics Consulting and Research (Biocore), LLC, Charlottesville, VA, USA.
Ann Biomed Eng. 2020 May;48(5):1524-1539. doi: 10.1007/s10439-020-02472-6. Epub 2020 Feb 7.
Despite the use of helmets in American football, brain injuries are still prevalent. To reduce the burden of these injuries, novel impact mitigation systems are needed. The Vicis Zero1 (VZ1) American football helmet is unique in its use of multi-directional buckling structures sandwiched between a deformable outer shell and a stiff inner shell. The objective of this study was to develop a model of the VZ1 and to assess this unique characteristic for its role in mitigating head kinematics. The VZ1 model was developed using a bottom-up framework that emphasized material testing, constitutive model calibration, and component-level validation. Over 50 experimental tests were simulated to validate the VZ1 model. CORrelation and Analysis (CORA) was used to quantify the similarity between experimental and model head kinematics, neck forces, and impactor accelerations and forces. The VZ1 model demonstrated good correlation with an overall mean CORA score of 0.86. A parametric analysis on helmet compliance revealed that the outer shell and column stiffness influenced translational head kinematics more than rotational. For the material parameters investigated, head linear acceleration ranged from 80 to 220 g, whereas angular velocity ranged from 37 to 40 rad/s. This helmet model is open-source and serves as an in silico design platform for helmet innovation.
尽管在美国橄榄球比赛中使用了头盔，但脑损伤仍然很常见。为了减轻这些损伤的负担，需要新型的冲击缓解系统。Vicis Zero1（VZ1）美式橄榄球头盔在其使用多方向的屈曲结构方面是独特的，这些结构夹在外壳和内壳之间。这项研究的目的是开发 VZ1 的模型，并评估其独特的特征在减轻头部运动学方面的作用。VZ1 模型是使用自下而上的框架开发的，该框架强调材料测试、本构模型校准和组件级验证。使用超过 50 项实验测试对 VZ1 模型进行了验证。CORrelation and Analysis（CORA）用于量化实验和模型头部运动学、颈部力和冲击器加速度和力之间的相似性。VZ1 模型与整体平均 CORA 得分 0.86 具有良好的相关性。对头盔顺应性的参数分析表明，外壳和柱体的刚度对头部的平移运动学影响大于旋转运动学。在所研究的材料参数中，头部线性加速度范围为 80 至 220 g，而角速度范围为 37 至 40 rad/s。这个头盔模型是开源的，是头盔创新的虚拟设计平台。
