Development of a finite element model of the human skull

Head injury is the most frequent injury resulting from traffic accidents. Head injury mechanisms are difficult to study experimentally due to the variety of impact conditions involved, as well as ethical issues, such as the use of human cadavers and animals. Finite element modeling is a comprehensive technique through which human head impact tolerance can be studied. A finite element human head model would ideally allow for the assessment of the injurious effects of different impact conditions and enable the development of enhanced head injury and protection criteria. The paper describes the development of a three-dimensional finite element model based on the anatomical features of the adult human cranium. The complex cranial geometry was measured from a series of two-dimensional computer tomography images. The CT scans were transformed with a self-developed preprocessor into a finite element mesh. To model the skull's impact responses, valid material properties are required. The mechanical characteristics of cranial bone were investigated experimentally at Heidelberg University's Institute for Forensic Medicine. To create a sample of material properties for use in the human head model, statistical analyses of the experimental results were undertaken. The tests were modeled with the finite element method and a numerical material model representing the mechanical properties of the human skull bone was developed. The first approach to validate the model and to investigate different boundary conditions by using experimental data is shown.