The subarachnoid space between skull and brain is filled with Cerebrospinal Fluid (CSF). In most FE head‐brain models applied in the field of transport safety, the fluid is modelled as an elastic material with a high bulk and negligible shear modulus. It can be hypothesized that a model considering flow might increase modelling quality of the head‐brain interface. In this study, experimental tests were conducted to provide data for the validation of the CSF modelling in an FE code under well‐defined and simple boundary conditions, using an artificial CSF and brain surrogates with realistic densities.
Three numerical models were established in LS‐DYNA, using either Mat_Elastic_Fluid, Mat_Null with an Equation of State, and Mat_ALE_Incompressible_Fluid for describing the CSF. For a fair comparison, an Arbitrary Lagrangian Eulerian (ALE) discretization was used for all models.
Pressure‐time response correlated very well with experimental results for all material models. Relative displacement, though, was not correctly simulated with the commonly used Mat_Elastic_Fluid. Results of experimental tests and numerical simulation were reconfirmed with a simple analytical model. The study showed that brain matter response in FE models, in particular relative displacement, can be considerably improved by applying a correct material model for the CSF.
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