The brain-skull interface (meninges) plays a critical role in governing brain motion during head impacts, yet computational models often simplify this interface using idealized contact conditions due to limited experimental data. This study presents an improved protocol combining experimental testing and computational modelling to determine the mechanical properties of the brain-skull interface under shear loading. Brain tissue and brain-skull complex samples were extracted from sheep cadaver heads and subjected to shear loading. Magnetic resonance imaging (MRI) was used to obtain accurate 3D geometries of the samples, which were then used to create computational grids (meshes) for simulation of the experiments using finite element (FE) models to determine subject-specific properties of the brain tissue and brain-skull interface. A second-order Ogden hyperelastic model was used for the brain tissue, and a cohesive layer was employed to model the brain-skull interface. Our results indicate that a cohesive layer captures the force-displacement and damage initiation of the brain-skull interface. The calibrated cohesive properties showed consistent patterns across samples, with maximum normal tractions ranging from 2.8-3.4 kPa and maximum tangential tractions from 1.8-2.1 kPa. This framework provides a foundation for improving the biofidelity of computational head models used in injury prediction and neurosurgical planning by replacing arbitrary boundary conditions with formulations derived from experimental data on brain-skull interface (meninges) biomechanical behaviour.

翻译：脑-颅骨界面（脑膜）在头部受冲击时对脑组织运动起关键调控作用，但由于实验数据有限，计算模型常采用理想化接触条件简化该界面。本研究提出一种结合实验测试与计算建模的改进方案，以确定剪切载荷下脑-颅骨界面的力学特性。从绵羊尸体头部提取脑组织及脑-颅骨复合样本进行剪切加载测试。利用磁共振成像（MRI）获取样本精确的三维几何结构，并据此建立计算网格（网格化模型），通过有限元（FE）模型模拟实验过程，以确定脑组织及脑-颅骨界面的个体化特性。脑组织采用二阶Ogden超弹性模型，脑-颅骨界面则通过内聚力层进行建模。结果表明，内聚力层能有效表征脑-颅骨界面的力-位移关系与损伤起始点。经标定的内聚力特性在样本间呈现一致规律：最大法向牵引力为2.8-3.4 kPa，最大切向牵引力为1.8-2.1 kPa。该框架通过采用基于脑-颅骨界面（脑膜）生物力学行为实验数据构建的模型公式替代任意边界条件，为提升用于损伤预测与神经外科规划的计算头部模型的生物保真度奠定了基础。