Mechanical properties of human spinal dura mater show rate dependency

The spinal dura mater is a tough membrane protecting the spinal cord. Its mechanical response, particularly under dynamic loading conditions (e.g., during vehicular collisions), can lead to severe medical complications. However, the mechanical properties of the dura mater across various strain rates as well as a sufficiently accurate material model to analyze its behavior remain underexplored. This study presents the results of uniaxial tensile tests conducted on spinal dura mater samples obtained from six donors (mean age 79.33 with standard deviation of 6.44), performed at strain rates of 0.5, 10, and 25 s⁻¹. The experiments utilized a custom-built uniaxial testing machine. The test enabled the determination of ultimate tensile strength, stretch at failure, and elastic modulus. The findings reveal an increase in the elastic modulus at higher loading rates, underscoring the significant rate dependence of the dura mater's behavior. Furthermore, a visco-hyperelastic constitutive model with validated material parameters is proposed, offering essential input for improving finite element simulations with dynamic spinal loadings analysis. Employing this model can facilitate more accurate predictions of spinal cord injury mechanisms and support the development of more effective automotive and road safety systems.