Numerical assessment of occupant responses during the bus rollover test: A finite element parametric study

Abstract

Rollover crashes of buses are usually associated with multiple impacts that can result in complex interactions between passengers and a bus superstructure. Although there have been a few field data studies that provide some insights into occupant injuries (e.g. severity and distribution of injuries) during the real-world bus rollover crash, because they had used post-crash data, the occupant kinematics and injury mechanisms were not completely detailed in their results. Based on a literature review, available numerical and experimental studies on a bus rollover safety have mainly focused on structural integrity rather than considering occupant responses in their assessment. In addition, their results about occupant responses in bus rollover crashes show some discrepancies in terms of the estimated injury distribution, severity, and causes. Therefore, the main objective of this study was to provide a more detailed understanding of the occupant kinematics and associated injury risk during the ECE R66 tilt table bus rollover test using validated finite element (FE) models. The ECE R66 tilt table rollover was simulated using a full finite element model of the bus. A 50th percentile male Hybrid III Anthropomorphic test device (ATD) and EuroSID-2re FE models were selected to simulate the occupant’s motion. Each ATD was seated adjacent to the impacted side wall and restrained with a 2-point seatbelt. Simulation parameters included two impact surface friction values and different side window conditions. The results indicated that both ATD estimated the highest injury risk when the partial ejection occurred. They predicted a similar injury risk for the head and thorax. The ES-2re estimated a very low risk of neck injury in all simulations, whereas the Hybrid III estimated the high risk of a neck injury. Finally, recommendations to potentially reduce the injuries were provided and possible future works were suggested.

Experimental and modelling research on coach passengers’ safety in frontal impacts

“…Joszko et al [11] carried out investigations evaluating the risk of neck injury in racing drivers who use the Hans system. Whereas, Sybilski and Malachowski [12] carried out numerical analysis a disabled driver with additional equipment designed for his safety and convenience.The occupant responses during the bus accidents have been also analysed in other research publications [13,14]. Analysis of head, cervical spine, thoracic, and leg trauma is a topic that is widely discussed in the scientific world not only in crash tests of cars [15,16] or intercity buses [17][18][19] but also e.g., in the military industry.…”

An Analysis of the Reliability of a Bus Safety Structure on Carrying Out the Numerical and Experimental Tests

“…Among all the traffic events caused by buses, an event related to bus rollover causes the maximum damage because it may cause even several fatalities per event. As compared to rollover of a car, a bus rollover occurs rarely; however, it is much more dangerous because of a larger number of passengers transported [ 1 , 2 , 3 , 4 , 5 ].…”

“…In the second stage, a passenger compartment is designed according to an individual order and then equipped on the chassis made in the first stage. In the second stage, safety of the manufactured vehicle and safety of traffic participants, passengers, and other persons, as well as satisfaction of the set safety requirements, and the growing needs of the community are considered [ 4 , 7 , 8 , 9 ].…”

“…Thus, a majority of manufacturers prefer to apply the finite element method for assessing the conformity of the structure to provisions of the United Nations Economic Commission for Europe (UNECE) Regulation No. 66 [ 4 , 9 , 11 , 19 , 20 ].…”