The effectiveness of child restraint systems has been very well proven in the case of frontal collision but the performance of the protective devices in sideimpact situation were not, as yet, clearly demonstrated.
This research was aimed at the development of a numerical method to simulate the behavior of a child passenger restrained in a protective device in the case of a vehicle side impact, considering vehicle body deformation. The model was mainly based on a multi-body method. However the side wings of the child restraint system and the vehicle body have been modeled by the finite-element technique, to allow for a better representation of the contacts between the child dummy, the restraining device and the structure of the vehicle and to make possible the simulation of the vehicle body deformation, based on available side impact test data. The model had been validated for side impact and we have used it to study the influence of the intrusion against the child dummy behavior in the case of side impact.
The intrusion influence is most important for the head injury criteria, being proportional with the impact speed. The study of various installation configurations showed that the usage of ISOFIX lower anchorages offers the best protection for the head, followed by the lower flexible anchorages and vehicle belt installation. The intrusion influence is most important when the child restraint system is installed using the vehicle safety belts, the results being much higher than for the case where the intrusion is not considered. Chest deceleration is less influenced by the intrusion and the three considered installation configuration give similar results. Although the results of the project successfully responded to the initial objectives, the model is offering a lot of possibilities of improvement, development and exploitation.