Research On Coach Impact Simulation And Occupant Injury Based On The Analysis Of Rollover Accidents

As the main means of passenger transportation in China, coach makes our life and travel more flexible and efficient. While coach traffic accidents also bring great threaten to the safety of our life and property. Especially in recent years, some rollover accidents of coach have caused the severe social influence. Therefore, research on the process and the occupant injury in coach rollover has an important economic and social significance to reduce the damage to occupant and protect passenger's safety in rollover accidents. It can also provide guidance for occupant protection and safety design of coach.This paper simulated the process of coach rollover that caused by sharp turn in the emergency situations by using computer simulation method, and then made an analysis on occupant dynamics response and occupant injury. From the perspective of accident case analysis, the paper analyzed three typical traffic accidents of coach rollover caused by sharp turn and summarized the causes of such accidents and their common characteristic, thus proposing a simulation method to simulate the process of this type of coach rollover accidents based on fishhook test regulations. Then, the collision process of coach rollover is simulated by using multi-body dynamics software MADYMO based on fishhook test regulations, and dynamics response and injury of occupants during the process of coach rollover are analyzed. Finally, occupant injuries were made an in-depth analysis under different influence factors, including the influence of the interaction between occupants, the occupant size, the initial condition and the safety belt on the occupant injury.The results show that occupant will be injured could both in pre-roll process and roll process of coach. The occupant in roll process has a higher risk of suffering injury, and the injury will be more serious. In coach pre-roll process, the head injury of occupant is normally described in minor or moderate which is rated as AIS<2. In coach roll process, the head injury is normally described in serious or severe injury which is rated as AIS>3, and the thorax injury is also severe that can be described as AIS>4. Occupant leg has the risk of fracture both in pre-roll process and roll process. Further research find that the interaction between occupants will aggravate head injuries of the occupant who seats on the aisle side and reduce head injuries of the occupant who seats next to the window. The child occupant has the higher risk of suffering injury relatively in the process of coach rollover. With the increase of the initial speed when the coach rollover is occur, the risk of suffering injury on head and thorax is also increased. With the decrease of the steering wheel angle when the coach rollover is occur, the risk of head injuries to occupant who seated by the window will reduce, while the risk of head injuries to occupant who seats on the aisle side will rise. Safety belt can effectively protect passenger when the coach rollover accident occurred, and it can also obviously reduce the risk of head injuries and leg injuries to passenger.