Influence of a Passenger Position Seating on Recline Seat on a Head Injury during a Frontal Crash

Abstract

Presently, most passive safety tests are performed with a precisely specified seat position and carefully seated ATD (anthropomorphic test device) dummies. Facing the development of autonomous vehicles, as well as the need for safety verification during crashes with various seat positions such research is even more urgently needed. Apart from the numerical environment, the existing testing equipment is not validated to perform such an investigation. For example, ATDs are not validated for nonstandard seatback positions, and the most accurate method of such research is volunteer tests. The study presented here was performed on a sled test rig utilizing a 50cc Hybrid III dummy according to a full factorial experiment. In addition, input factors were selected in order to verify a safe test condition for surrogate testing. The measured value was head acceleration, which was used for calculation of a head injury criterion. What was found was an optimal seat angle −117°—at which the head injury criteria had the lowest represented value. Moreover, preliminary body dynamics showed a danger of whiplash occurrence for occupants in a fully-reclined seat.

The Effect of Changing the Angle of the Passenger Car Seat Backrest on the Head Trajectories of the 50th Percentile Male Dummy

“…Furthermore, it should be noted that lumbar spine injuries are well-researched in the literature, but there are few studies focusing on body dynamics in a reclined position. The diversity of seat belt reactions and altered body dynamics can negatively affect the effectiveness of airbags, especially when dealing with submersion, which increases the risk of head injuries due to the greater distance from the airbag [ 47 , 48 , 49 ].…”

Passenger muscle responses in emergency braking events with reclined seating

“…Laakmann et al 23 and Matsushita et al 24 showed that the reclining posture could increase the risk of injury for the occupants, especially to the head and neck. Another study found that starting from 117° relative to the horizontal, when the seatback angle increased, the value of Head Injury Criterion also increased 25 . Reclined seating can make the head rotate during a collision, which increases the risk of neck injury 26 .…”

Evaluation of the Reliability of the Shoulder and Knee Joint of the KPSIT C50 Dummy Adapted to Crash tests carried out at low speeds.

“…It should be noted that the ideal design solution for dummy would be a solution that would ensure the lack of frequent calibration and the durability and reliability of the joints. [30,31,32].…”

“…Fig.7. An example of the course of the components of the moment of resistance[30].𝑀 = 𝑀 𝑘 (𝜟𝝋) + 𝑀 𝑐 (𝜟𝝋̇) + 𝐶 (1)Where:𝑀 𝑘 (𝜟𝝋) -a componentthat is a function of the joint angle, 𝑀 𝑐 (𝜟𝝋̇) -component that is a function of the angular velocity at the joint, 𝐶 = 𝑀 𝑜 − 𝑀 𝑘 (𝜟𝝋 𝒐 ) -constant selected on the basis of initial conditions, 𝑀 0 , 𝛥𝜑 𝑜 -torques and initial joint angles.…”