A large number of cars used in today’s road traffic have by now been fitted with airbags for frontal and side impact. In case of an accident, the built-in sensor in the vehicle registers the decelerations and directions of impact taking place and activates either the front or the side airbag during the accident. The airbag is by no means always activated in accordance with the accident. A documentation of a scientific team of researchers of the Medical University Hanover has shown different collisions configurations and analysed the correct or incorrect deployment of airbags.
Through detailed analysis and computer aided reconstruction of the course of the accidents it was possible to reproduce the moving behaviour and the deformation characteristics of the vehicles and to evaluate whether there really had been a faulty activation or whether the cause of non-deployment could be found in different impact parameters.
The analysis shows that often the vehicles skidded before the collision, mainly collided diagonally with the accident partner, where during the compression phase of the deforming vehicle structures the airbag was activated as a consequence of the increase in deceleration. However, the whole deformation phase can only be considered as being finished when the compression is completed with an exchange of the impact impulse and only then do the real deformation characteristics ensue.
The special time characteristics of the relative movements of the passengers and the injury mechanics during the collision phase are discussed in the paper. Proposals for optimisation of the airbag system are made.