Proposal of an International Harmonized Dynamic Test Standard for Seats/Head Restraints

A dynamic seat test standard proposal has been established by the Institute for Vehicle Safety, German Insurance Association (GDV) together with other institutions (ETH Zurich, Autoliv Germany, TU Graz) to define a test procedure for seat/head restraint design. By optimizing the total safety system integrating both seat design and head restraints, an improved protection against cervical spine distortion injuries in rear end collisions is the aim. The proposal was discussed and refined in different working groups also with car and seat manufacturers and should define a basic test for legislation in ECE-GRSP and ISO, and for consumer benchmark testing. The paper describes the current status of international activities. The basic test standard is a sled test with a j v of 16 km/h (10 miles) and a representative car crash pulse of 6-8 g. The test specifications are derived from real-world accidents. The Institute for Vehicle Safety, Munich, has established a large-scale accident material of 15,000 car-to-car crashes representing every fifth collision within 1 year in Germany. A sub-sample of 517 rear-end collisions with passengers suffering from cervical spine distortion (CSD) injury had been analyzed technically and medically. From the accident reconstruction, the most typical accident scenario was evaluated, which should describe requirements for improved seat/head-restraint systems. The data show that the typical accident configuration is a 0-5° angled impact with almost full overlap and a j v between 10 and 20 km/h. Additionally for higher impact velocities a seatback deflection test, if possible a static one, should be added. For active systems, only a low-velocity test with 10 km/h is under discussion. The test proposals for ISO, EEVC, ECE-GRSP, and International Insurance Whiplash Prevention Group differ slightly due to their different standardization requirements and testing needs. But this proposal should form a common basis and should contribute to the still possible aim that the dynamic seat/head-restraint test will be harmonized worldwide instead of accepting different procedures, parameters, and dummies.

Keywords:

• Whiplash
• Sled Tests
• Rear End Impacts