Passive Safety Solutions on Coach according ECE R29: Experimental and Numerical analyses

Abstract

Accidents involving vehicles for public transportation can endanger both the driver and the passengers, due to the proximity of the impacting region, and the correspondent violation of the safety cell. The vehicle structural design and the high rate of energy or accelerations involved are important aspects during an accident. To improve the current design applied to public vehicles, structural optimization research, with the goal of improving safety, is needed.The objective of this study is the development of new technologies for new passive safety solutions, employed on coaches. Initially, a study on the improvement of the driver safety, during a frontal collision, will be developed. The final outcome of the present study is the development of new generation of coaches outfitted with technology capable of reducing the impact's unforeseen consequences.To study the structural behavior of a coach (M3 Class III vehicle) in the event of a head-on collision, the ECE R29 Regulation will be considered. The current safety standards only focus on the certification of large vehicles with separate driver's cabs, with no requirements addressing coaches. An experimental setup was built to conduct a frontal crash test. An impactor hanging by two steel bars impacted against the structure crushing it, with an energy of 55 kJ. A Digital Image Correlation (DIC) system, strain gauges, and accelerometers fitted on the structure were used for data acquisition. The experimental setup was also numerically simulated, using the Finite Element Method (FEM). A dynamic explicit model was considered to determine the dynamic structural response. The evolution of the strain, accelerations and displacements were obtained and compared with the experimental results. The internal energy was evaluated and compared to the reference value. With the different obtained results, it was possible to decide whether the current models satisfy the safety criteria of or whether a solution proposal is necessary to improve the outcomes.