Search Results

Dummy responses in a crash test can vary depending not only on the change of velocity but also on how the impact was generated. Literature reporting how acceleration pulses can vary in cars impacted in different configurations is limited. The aim of this study was to collect and categorise different acceleration pulses in 3 different types of rear collision. The acceleration pulse resulting from a solid, 1000 kg, mobile barrier test at 40% overlap and an impact velocity of 15 km/h was studied for 33 different cars. Seven cars were impacted at 100% overlap at higher impact velocities using the same mobile barrier. Acceleration pulses from two different car types in real-world collisions producing a similar change of velocity were also analysed. The results from the barrier tests show that a similar change of velocity can be generated by a large variety of pulse shapes in low velocity rear impacts.

Neck injuries in rear-end collisions are usually caused by a swift extension-flexion motion of the neck and mostly occur at low impact velocities (typically less than 20 km/h). Although the injuries are classified as AIS 1, they often lead to permanent disability. The injury risk varies a great deal between different car models. Epidemiological studies show that the effectiveness of passenger-car head-restraints in rear-end collisions generally remains poor. Rear-end collisions were simulated on a crash-sled by means of a Hybrid III dummy with a new neck (Rear Impact Dummy-neck). Seats were chosen from production car models. Differences in head-neck kinematics and kinetics between the different seats were observed at velocity changes of 5 and 12.5 km/h. Comparisons were made with an unmodified Hybrid III. The results show that the head-neck motion is influenced by the stiffness and elasticity of the backrest as well as by the properties of the head-restraint.

Several investigators have noted limitations of the most commonly used dummy in rear impact testing, the Hybrid III. A dummy for rear impact testing, the BioRID I, has previously been presented. It was a step towards an effective tool for seat performance testing, but it was concluded that its neck extension and T1 upward motion were too small and that its user- friendliness could be improved. A new BioRID prototype has been developed. It has new neck muscle substitutes with damping and elastic elements that are independent of each other and fitted inside the torso. The new neck muscle substitutes extend to T3 and thus also load the upper thoracic spine. The new dummy has a softer thoracic spine and a torso made of softer rubber than was used for the original dummy. The BioRID prototype''s performance was compared to that of volunteers, the BioRID I and Hybrid III in rear impacts at ΔV=7 km/h.