Finite element modeling of cervical vertebrae in high Gz environment

Abstract

A comprehensive, geometrically accurate, nonlinear FE model of head and cervical spine wad developed with geometrical data based on the actual geometry of a 68 year-old ale cadaver specimen. Validation of the FE model was conducted under static physiological loading, near vertex drop test, and whiplash test. The results show that the corresponding predicted results of motions of each motion segment agree well with the published experimental data. The validated C0-C7 FE model was then further analyzed to investigate the kinematic response of the whole head-neck complex under ejections. The results show that during ejection process, obvious hyper-flexion of the head-neck complex could be found after the acceleration onset stage. The peak acceleration and duration time were more important in affecting the occurrence of neck injury than acceleration rate. The effect of the muscle to reduce the rotation and stress development in the neck is obvious, it is important for pilots to restrain muscle before ejection. From the current study, it was found that stress variation histories in the neck were consistent with the rotational motions of the motion segments under dynamic loading. The corresponding maximum rotation angle of the each motion segment may help to determine the potential injury to cervical spine under dynamic conditions.