Research on the Submarining Injuries of Occupants in Large-angle Sitting Postures

With the development of automotive automation technology, large-angle seat are gradually becoming popular and have revolutionized the traditional sitting posture of vehicle occupants, posing challenges to the vehicle occupant protection performance. To evaluate the submarining risk of occupants and the injury characteristics in normal and large-angle sitting posture, and the improvement measures for preventing submarining of occupants in large-angle sitting posture, this study conducts a comparative analysis of kinematic posture and submarining risks of occupants in normal and large-angle sitting posture, studies the movement trends and injury characteristics of occupants in large-angle sitting posture, as well as the improvement measures for preventing submarining, based on the THUMS50 model that can meet the requirements of large-angle sitting posture. The results show that: compared with the normal sitting posture, the seat backrest has a larger inclination angle in the large-angle sitting posture. In this posture, the occupant is in a semi-reclining state. During the collision, the pelvis is more likely to move forward, thus resulting in submarining. When submarining occurs to occupants in the large-angle sitting posture, the head, abdomen, and pelvis move forward to a relatively large extent, resulting in greater injuries to the head and abdomen compared with the normal sitting posture. Increasing the seat cushion tilt of the large-angle seat can disperse the load concentrated on the abdomen to various parts such as the cervical spine, chest, and lumbar spine, effectively alleviating the submarining of occupants in the large-angle sitting posture.