Numerical study on the influence of superstructure configuration on coach rollover resistance performance

Coach rollover is one of the most dangerous accidents with respect to fatalities and injuries. The superstructure of a coach has an essential and vital impact on the rollover crashworthiness. To design the optimal superstructure of a coach requires that the effects of superstructure configuration on rollover crashworthiness are thoroughly understood. In order to find the design guidelines for superstructure configurations, this paper studied the influence of coach superstructure configuration on rollover resistance performance. A baseline finite element (FE) model of an intercity coach with semi-integral body is developed. Seven FE models are derived on the basis of the baseline model considering different superstructure configurations, such as closed rings, joints between the side-wall and floor, side window pillar structure as well as distances between the window rails and waistrail. Numerical simulations of rollover test are performed in accordance with the technical prescriptions in ECE Regulation 66. Performance indices, including residual space intrusion amount, energy absorption of each assembly, deformation mode and impact force are calculated and investigated. Results show that the closed rings, the joints between the side-wall and floor assembly as well as structural configurations of the side window pillars have significant effects on the rollover crashworthiness, but the rollover resistance is not sensitive to the distance between the window rail and waistrail. Design guidelines are proposed for coach superstructure to improve rollover crashworthiness based on comparative analysis on performance indices.