EXPERIMENTAL ASSESMENT OF THE STRENGTH OF COACHES STRUCTURES AFTER COLLISION REPAIR

Abstract

[EN] Vehicles repair after an accident and the quality assurance of the repair is a major safety issue. If the vehicle type category is M3, collective road transport vehicles, there is an additional concern due to their high number of occupants, the responsibility of third parties transport and the severity of some type of collisions such as rollovers. Moreover it has to be considered that the high cost of these vehicles and the investment made on them by the transport companies makes it profitable to proceed to their repair after some accidents. In this work it is quantified the loss of energy absorption capabilities of the structural steel profiles of rectangular hollow section used in the construction of these vehicles. The deformation energy has been measured by means of bending tests and calculating the bending moment vs bending angle curve. The load has been applied to reach 10, 15 and 20 permanent bending angles, representing those rollover structural deformations found on coach collisions of different severities. All test specimens have been straightened and bended up to 20 degrees some in the same bending direction as initial bend test and some in the opposite direction. The results show a significant loss of strength of the profiles and the final influence on a repaired structure has been quantified modeling with a FEM model a standard Regulation ECE 66 of Geneva type approval test. It is then demonstrated how it should be defined requirements for repaired buses and coaches after their repair of structural damages in collisions.