English abstract : The current European regulation on testing and licensing of child protection systems for passenger cars (ECE-R44–03) includes dynamic tests for frontal-impact and rear-impact simulation. Side impact has not been allowed for to date even though the injury severity and consequential costs are high. Unlike frontal impact and rear impact, side impact is characterised by a direct load admission as the result of intrusive structures. The child protection system and the child are subjected directly to high contact forces. Injuries to the head and neck area of children in child protection systems are frequent and severe in this case. Consequently, an ISO (International Standardisation Organisation) working group has been investigating development of a test method for testing child protection systems in side-impact accidents since 1993. The objective and corresponding ideas and concepts of parties involved have been controversial through to today so that it has not yet been possible to reach a definitive agreement within the framework of the working group. The aim of the present study, as a conclusion of a project conducted by the Federal Highway Research Institute (BASt) and the Motor Vehicles Faculty of Berlin Technical University, is to comprehensively present the complex problems relating to the topic and, at the same time, offer an integral proposal for solving the problem. To this aim, the partial results of the ISO working group were structured and analysed in an initial step. Gaps in available knowledge were detected and eliminated in a further step. All partial results were presented, discussed and also largely accepted within the framework of the ISO working group. The current status of ISO working group 1 is thus crucially influenced by the results achieved here. As the core of the present study, the concept for a test method was developed, implemented and tested at Berlin Technical University. The essential parameters of the real side impact, such as: acceleration level of the impacted passenger car; delta-v of the impacted passenger car; maximum intrusion on the impacted passenger car and maximum intrusion velocity in the head area are presented. Unlike current, complex sled test methods which are used to develop side airbags for instance, the static and dynamic intrusion configuration of a real passenger car side structure is greatly simplified but adequately presented. The results indicate that, in principle, it is possible to analyse the protection potential of backward-pointing and forward-pointing child protection systems with this procedure. The quality of side impact imaging is high and, at the same time, reproducibility of the measured results is very good. Thus, the tests indicate that the kinematics of the head and neck area are essentially dependent on the configuration of the child protection system in the side area. Adequately large lateral supports are able to support the head over a large area and thus avoid direct contact with intrusive structures. At the same time, the high lateral inclination of the cervical vertebral column is reduced. The loads on the head are, however, high in the case of all child protection systems tested and lie well above discussed limit values. If we consider the child protection system lateral support cushioning more precisely, we can see that this is either not present at all or is present only in rudimentary form. Modifications which were implemented on child protection systems in the concluding phase do, however, indicate that even simple technical measures are able to significantly lower the loads in the head area. The test method submitted with this study offers manufacturers of child protection systems and legislators the option of revealing vulnerabilities in child protection systems and implementing modifications in targeted manner. Allowing for the real side impact ensures that all optimisations on the part of the child protection system manufacturers are also able to positively impact on passive safety of children in passenger cars. A maximum reduction of around 10 % in the number of children seriously injured or suffering lethal injuries as passenger car occupants is realistic with 100 % market penetration of optimally designed products. This corresponds to an approx. 10 % reduction in the number of children killed and around 200 seriously injured children less per annum in Germany. (Author/publisher)
Abstract