Research on Injury Protection for Rear Pregnant Occupants in Frontal Impact

Abstract

Abstract This paper investigates the protective effects of restraint systems, specifically the three-point and combined safety belts, on pregnant occupants during transportation safety. The goal is to explore potential injury risks and enhance safety measures. Firstly, a restraint system model of the rear female occupant in the frontal full-width collision is established and validated. Secondly, the finite element model of the uterus at 30 weeks of pregnancy is established and coupled with Hybrid III 5th female facet human model to build a pregnant occupant model. Finally, according to the injury mechanism of the pregnant occupant and fetus, a comprehensive injury index WICp is proposed to assess the injury of the pregnant occupant and fetus. Research has been conducted on the effectiveness of wearing both a combined safety belt and a three-point safety belt by the pregnant occupant under various impact loads to ensure optimal protection. The results reveal that compared with the three-point safety belt, the combined safety belt worn by the pregnant occupant could reduce the abdominal compression value by 38% on average, decrease the Uterus Placental Interface (UPI) strain at the uteroplacental intersection by an average of 18.3%, and make the average reduction of the comprehensive injury by 13.4%. When the impact speed is less than 55km/h, the UPI strain value of the uteroplacental interface will not exceed the limit value of 60%. As a result, the risk of placental abruption for the pregnant occupant is reduced, and the protective effect during transportation safety for the pregnant and fetus is enhanced. The research results provide a scientific theoretical basis and reference value for pregnant occupants and fetuses to develop safer, more reliable, and more comfortable seat belts.