Vehicle Safety and Dynamics Laboratory Wrocław University of Science and Technology
naukowcy
Determination of injury criteria and passenger kinetics considering variable seat positions during a passenger car accident
Dziedzina nauk inżynieryjno-technicznych / inżynieria mechaniczna (2018)
Founding: This study was financially supported by the MINIATURA 7 (2023/07/X/ST11/00156) grant from the National Science Centre (NCN). The research was conducted at the Vehicle Safety and Dynamics Laboratory of Wrocław University of Science and Technology. The experiments were planned and analyzed in accordance with the PN-ISO 3534-3 standard. The presented curves represent the averaged value from three consecutive measurements.The input parameters were a crash pulse ranging from 15g to 30g and the seatback angle (i.e. 21, 38 and 55 degrees). The measured parameters were head acceleration, chest acceleration, and angular velocity in the chest and head. By integrating the angular velocity, the angles of the head and chest in the XYZ axes were determined and presented as a function of time. The research showed that the dummy's head acceleration is close to the acceleration of the crash pulse when the seatback is in an upright position. Previous tests conducted at the Vehicle Safety and Dynamics Laboratory of Wrocław University of Science and Technology with pulses up to 5g indicated that head acceleration exceeded the crash pulse. In high-energy tests, with the seat in the nominal position, head acceleration slightly exceeds the crash pulse. The more the seat is reclined, the greater the difference between head acceleration and the crash pulse, with the largest differences observed when the seatback is fully reclined. Until the seatbelt locks, the entire torso and head of the dummy move forward in parallel. In low-pulse scenarios (up to 5g), previously studied, the hips are first restrained by the lap belt, followed by the chest contacting the shoulder belts, causing a significant whiplash motion of the head. In high-pulse scenarios, regardless of the seatback angle, the torso moves in parallel, and when restrained by the belts, the posture does not straighten as it does in low-energy pulses. Consequently, with a reclined seat, the forward movement of the head increases the risk of neck injury. In extreme cases, for the highest crash pulse and with the seatback fully reclined, the angular velocity of the head exceeded 1990°/s, meaning that within 65 ms, the head changed its angle by more than 70°. Video analysis showed the greatest neck flexion in the lower parts, indicating that the more reclined the seat, the greater the risk of injury to the T1 and C7 vertebrae. In low-energy tests, neck injuries can be expected due to vertebral compression, causing an injury mechanism similar to whiplash. Such injuries always occur in rear-end collisions, not frontal ones. However, in high-pulse scenarios, injuries result mainly from neck stretching. Despite varying angles and increasing crash pulses, no 'submarining' phenomenon was observed. The only lumbar injuries to the dummy may result from the tailbone striking the seat cushion.
Sled test
Out of Position
Injury Criteria
Frontal Protection Systems