Abstract
In the last years, the slow rear-end collision accompanied by the whiplash phenomenon has been a topic of discussion, especially for insurance companies and various consumer organisations. EuroNCAP and IIWPG developed pragmatic measurement procedures to predict the risk of whiplash, although the biomechanics of the phenomenon is not fully understood up to now.
Therefore the development of whiplash preventing seats got a high focus in the design process of a new car.
The seat in general is designed to sit comfortable on it for longer trips and to be safe by a crash and has therefore to fulfil several requirements. On the one hand customers ask for enough clearance between head and head restraint, on the other hand this is negatively in case of a rear accident.
These different issues could only be solved by means of a combined process of testing and simulation. The challenge of simulation was to build up biomechanical dummy models and finite element seat models considering the influence of the structure and the foam. In parallel it was important to study all the effects of different seat parameters. At present the prediction of simulation is close to the test results. Nevertheless today there are some gaps between testing and simulation, so we still have to go on improving our tools. In the presented paper, there is a short description of the seat requirements, the whiplash test methods and their weaknesses, the main parameters for whiplash prevention, the status quo of simulation and some examples of technical solutions.
Conclusions are: - Comfortable seating combined with whiplash prevention is possible - SAE measurement has to be harmonized by using new VDA standard and seating procedure has to be improved - Simulation today has a good correlation to the tests, but improvement of seat/ dummy model is still necessary
Keywords: Design for whiplash, testing and simulation, conflicts, whiplash achievements