Towards Determining Mechanical Properties of Brain–Skull Interface Under Tension and Compression

This study establishes a new experimental–computational framework to quantify the mechanical behavior of the brain–skull interface under controlled uniaxial tension and compression. Sheep cadaver heads were dissected to extract intact brain–skull complex samples preserving meninges, cerebrospinal fluid space, arachnoid trabeculae, and cortical structures. High-resolution 3D geometry was captured through T2-weighted MRI and converted into fully hexahedral finite element meshes for subject-specific analysis. Using tensile and compressive loading, the authors demonstrated non-symmetric mechanical behavior: the brain–skull interface exhibited clear mechanical failure under tension, with delamination occurring between arachnoid barrier cells and the pia–arachnoid complex, while no obvious failure occurred under compression. Subject-specific Ogden hyperelastic parameters for brain tissue were calibrated from tension and compression data (μ ≈ 1200 Pa, α ≈ –6.3). Finite element simulations matched the experimental force–displacement curves with high fidelity, revealing limitations in commonly used modeling assumptions such as rigid tie constraints or frictionless sliding. The results highlight the need for improved constitutive and interface models in computational head simulations used for neurosurgical planning and traumatic brain injury prediction.