A Study on Affections of Different Skull-Brain Interface Modeling Approaches on Intracranial Responses in Finite Element Analysis

The skull-brain interface is structurally complex, and various simplification methods have been employed in existing head models to simulate the interaction between the skull and the brain. The modeling approach of the skull-brain interface determines how loads are transmitted to the interior, which is critical for accurately simulating head injuries. Thus, understanding the impact of current skull-brain interface modeling approaches on intracranial simulation results is significant. This study aims to explore the influence of different skull-brain interface modeling methods on the results of finite element models during the development of Advanced Chinese Human Body Models (AC-HUMs) based on the LS-DYNA solver. By comparing the responses of rigidly bonded connections (tied Contact), failure-allowing bonded contacts (tiebreak Contact), shared nodes, and arbitrary Lagrangian-Eulerian (ALE) methods under the Nahum 37 test load conditions, the study analyzes the effects of different modeling methods on pressure and deformation trends. Additionally, varying the failure values of tiebreak contact allows for the calculation of intracranial pressure responses under the same load conditions, revealing the influence of failure values on intracranial pressure responses. The results indicate that only the tiebreak model can simulate the transition from negative to positive pressure observed in experimental results, with significant variations in simulation outcomes corresponding to changes in failure values. This research provides a reference for the selection and optimization of finite element head modeling methods. Tiebreak contact is a better choice if the interface tearing effect needs to be modelled under linear impact conditions; Tied contact and shared nodes methods provide better computational stability and are more considered at the early stage of modelling; the ALE method is more common in studies for specific injuries and should be used in conjunction with the previously mentioned methods.