Computional and Experimental Mechanics Validation of a Detailed Human Body Model in Rear Impact Conditions

Under supervision of ir. M.J. van der Horst (TUEjUM) and dr.ir. A.J. van den Kroonenberg (TNO) Neck injuries occur frequently in car crashes, especially in rear-end collisions. The im-plications for society are serious, as the social costs are high and the complaints are long-lasting. Knowledge of injury mechanisms through which loads cause injuries to the neck is incomplete, especially for minor injuries. In an attempt to minimize the severity and the number of the neck injuries, numerical and experimental study is done to investigate the dynamic behaviour of the head neck system in rear-end collisions and to design safer vehicles. In this study the head-neck system in a global human body model was replaced by a detailed head-neck model. The global model, the detailed head-neck model and the detailed human body model are described and evaluated by comparison of the model responses to post mortem human subjects (PMHS) responses to a 7g rear impact. Responses that were compared are: linear and angular accelerations of the head, hor-izontal and vertical displacements of the head, the neck length, and rotations of the head and the neck. Finally the various models are compared to each other. The main conclusions are that the rotations and displacements of the head-neck system can be well predicted by the global model, as opposed to the head accelerations. The CMN model is not capable of predicting a 7g rear impact correctly and large head and neck rotations and displacements occur. However, this model is suited for predicting frontal and lateral impact. The detailed model is not able to simulate the PMHS ex-periments correctly, either, but the head accelerations of the detailed model are closer to the PMHS corridors than those of the global model. Finally it can be stated that the differences between the responses of the CMN model and the detailed model are small and that considering the calculation times, it can be recommended to use the global model for design applications; the CMN model for injury mechanism studies and the detailed model for refinement of designs and injury studies