Search Results

A previously developed finite element human head/cervical spine model was further enhanced to include the major muscles in the neck. The head/cervical spine model consists of the skull, C1-C7, disks, facets, and all the ligaments in this region. The vertebral bodies are simulated by deformable bodies and the soft tissues in the cervical spine are modeled by nonlinear anisotropic viscoelastic material. The motion segments in the cervical spine model were validated against three-dimensional cadaver test data reported in the literature. To simulate the passive and active muscle properties, the classical Hill muscle model was implemented in the LS-DYNA code and model parameters were based on measurements of cadaver neck musculature. The head/neck model was used to simulate a human volunteer flexion whiplash test reported in the literature. Simulation results showed that the neck muscle contraction and relaxation activities had a significant effect on the head/neck motion.

A finite element human thorax model was developed for predicting thoracic injury and studying the injury mechanisms under impact. Digital surface images of a human skeleton and internal organs were used to construct the three-dimensional finite element representation of the rib cage, the heart, the lungs, and the major blood vessels. The mechanical properties of the biological tissues in this model were based on test data found in the literature. The constitutive equations proposed in the literature for describing the mechanical behavior of the heart and the lungs were implemented in the code for modeling these organs. The model was validated against cadaver responses for both frontal and lateral impact. Good correlation between the model and the cadaver responses were achieved for the force and deflection time-histories.