Development and Numerical and Experimental Validation of an Anti-Intrusion Device for Protecting the Battery Compartment in Electric Buses

The behavior of mechanical structures subjected to impacts is a topic of great relevance, with one of its applications being in the context of collisions on urban roads. According to data obtained from the electric bus monitoring platform E-Bus Radar, the fleet of vehicles with this means of propulsion has grown significantly in the last 6 years. Just from 2022 to 2023, the growth was 51%, jumping from 2669 to 4020 registered vehicles in Latin America. In this context, the present study investigated the behavior of the rear structure of an electric bus - EB in a rear-end collision scenario. The study of this region was motivated by the fact that it houses 4 out of the 12 battery packs and other electrical components. The main objective of this work is to evaluate the efficiency of the anti-intrusion and impact absorption mechanism to ensure the integrity of the batteries. Since damage in a collision can release different types of flammable electrolytes and even trigger a fire, posing a significant risk to passengers and other individuals near the vehicle in addition to its high added value. A module of the rear structure of the bus was manufactured and tested numerically and experimentally based on the pendulum test according to Resolution No. 629 of CONTRAN. The anti-intrusion device proved effective in protecting the batteries and racks, meeting the proposed approval criterion of preventing any component of the structure from contacting the batteries during impact. Subsequently, after calibrating the simulation with the rear module of the structure, the entire bus was discretized and numerically simulated for impact against a standardized rigid barrier and a numerical model of a light vehicle, both colliding with the rear of the electric vehicle at 50 km/h, where the anti-intrusion mechanism also proved effective. Finally, the experimental rear impact test of the complete bus versus an SUV also succeeded in ensuring the safety of the batteries.