Investigation of biomechanics of skull structures damages caused by dynamic loads.

PURPOSE: The aim of the study was to examine the influence of cranial sutures on the crack behaviour of a human skull after the impact. The authors focused on the assessment of skull breaking nature, based on a real-world vehicle-to-bicyclist accident. In the state of the art, there is still no consensus about sutures mechanical properties. Currently, most of the numerical head models do not have distinguished cranial sutures. METHODS: The authors compared different elastic properties for cranial sutures and their influence on the nature of the skull fracture. The mathematical and numerical modelling have been applied to mimic the nature of the skull fracture. The LS-DYNA explicit code with material models featuring the erosion of finite elements was used. The models of the skull with different cranial sutures properties were impacted against a validated front-end of a vehicle. RESULTS: Various fracture patterns were obtained for different material properties of the sutures and the results were compared to a model without the cranial sutures. Based on the results, a graph was plotted to indicate differences in sutures energy absorption capabilities. The numerical results were supported by the mathematical modelling. The developed diagram may enable better understanding of the complex mechanical phenomena on the suture interface. CONCLUSIONS: Biomechanical evidence was provided for the important role of the sutures in numerical models as well as their significant influence on the biomechanics of skull fractures caused by dynamic loads.