No abstract

The oblique impact is the second most common frontal impact, in which both the forward and lateral accelerations are applied to the occupant. It is noticed that the oblique impact is a primary source of serious injuries, in which the chest injuries are mostly fatal through the statistics of traffic accidents. This study aims to investigate the characteristics of the occupant’s chest injury in the frontal oblique impact. First, a model with a sled and a Test Human Occupant Restraint (THOR) dummy is established. Second, an acceleration curve with a peak of 9.0 g is applied to the sled. Then 11 sets of simulations with different impact angles and belt peak loads are conducted to evaluate the occupant’s chest responses. Results indicate that there is a negative correlation between belt peak force and injury outcomes, while there is a weak correlation between chest injury and impact angle. With the increase of the belt force limit, the chest deflection at Lower Left (LL) would increase by 37.9%, and the acceleration at LL would increase by 23.1%. Meanwhile, the Viscous Criterion (VC) at LL would increase by 61.4%. However, the relationship between the impact angle and injury drawn by VC and acceleration is inconsistent. Additionally, in all simulations, the maximum deflections are captured at the LL, while the maximum VCs happens at Upper Right (UR) or LL. It is demonstrated that a seatbelt with a lower peak force is friendly to the occupant’s chest under all the impact angles. This study can provide a reference to the study of chest injury in the oblique impact.

Liver injury is one of the most fatal injuries in traffic accidents. To deeply study response characters of this injury under the unique impact condition, three impact tests are conducted based on the human body model and constraint systems of a car. This study is conducted based on the numerical method and adopts the orthogonal experimental design to deeply investigate the relationship between biomechanical responses and the impact loading variables. Data were collected and analyzed with the rotation of the liver in three planes and the distance change relative to the spine. Results show that in the near-side oblique impact, the maximum stress of the liver is captured as 10.041 MPa. In addition, the rotation angle of the liver in the three planes is the largest in the far-side oblique collision. In general, a more significant influence on the compression and movement of the liver is obtained from the near-side side collision, mainly because the door directly hits the left side of the occupant during crash process due to the limited space between door and occupant. In a far-side oblique collision, a buffering effect of the seat back to the driver does not play the role during the crash. As a result, the seatbelt slips off the occupant’s shoulder, resulting in a high displacement of the upper body. Thus, ensuring the restraint effect of the seatbelt may be a crucial problem for far-side oblique collision. This study can provide a reference to the occupant safety protection during vehicle accidents.