Zhou Zhou, Li Xiaogai, Kleiven Svein, Hardy Warren N
Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
Virginia Tech-Wake Forest Center for Injury Biomechanics, Blacksburg, Virginia, USA.
Stapp Car Crash J. 2019 Nov;63:1-27. doi: 10.4271/2019-22-0001.
Brain strain secondary to head impact or inertial loading is closely associated with pathologic observations in the brain. The only experimental brain strain dataset under loadings close to traumatic levels was calculated by imposing the experimentally measured motion of markers embedded in the brain to an auxiliary model formed by triad elements (Hardy et al., 2007). However, fidelity of the calculated strain as well as the suitability of using triad elements for three-dimensional (3D) strain estimation remains to be verified. Therefore, this study proposes to use tetrahedron elements as a new approach to estimate the brain strain. Fidelity of this newly-proposed approach along with the previous triad-based approach is evaluated with the aid of three independently-developed finite element (FE) head models by numerically replicating the experimental impacts and strain estimation procedures. Strain in the preselected brain elements obtained from the whole head simulation exhibits good correlation with its tetra estimation and exceeds its triad estimation, indicating that the tetra approach more accurately estimates the strain in the preselected region. The newly calculated brain strain curves using tetra elements provide better approximations for the 3D experimental brain deformation and can be used for strain validation of FE models of human head.
头部撞击或惯性负荷引起的脑应变与脑部的病理观察密切相关。唯一一组在接近创伤水平负荷下的实验性脑应变数据集是通过将实验测量的嵌入大脑中的标记物的运动施加到由三元组元素构成的辅助模型上计算得出的（哈迪等人，2007年）。然而，计算应变的保真度以及使用三元组元素进行三维（3D）应变估计的适用性仍有待验证。因此，本研究提出使用四面体元素作为估计脑应变的新方法。借助三个独立开发的有限元（FE）头部模型，通过数值复制实验撞击和应变估计程序，对这种新提出的方法以及先前基于三元组的方法的保真度进行评估。从整个头部模拟中获得的预选脑元素中的应变与其四面体估计显示出良好的相关性，并且超过其三元组估计，表明四面体方法能更准确地估计预选区域中的应变。使用四面体元素新计算出的脑应变曲线为3D实验性脑变形提供了更好的近似值，可用于人头FE模型的应变验证。
