Rear underrun protection design in heavy vehicle with energy absorbing properties

Every year, thousands of traffic accidents happen in our country's highways. Considering the distribution of these accidents, the collision of light vehicles with heavy vehicles and entry into the bottom of the vehicle as a result of crushing the vehicle and seriously injuring the passengers, have an important place. Despite the regulations in force, resulting in deaths of such accidents, the lack of protective designs used in vehicles. Rear underrun protection devices for heavy commercial vehicles such as trucks and tractors used for cargo handling are designed and implemented in accordance with the UN ECE R58 regulation. This regulation specifies the criteria that must be met for the rear protective bumpers to be used in heavy vehicles. In this study, the details of the R58 regulation were investigated, and literature survey was conducted, and the design of the rear underrun protection was investigated. In this context, new rear underrun protection device designs have been made and finite element simulations have been carried out on the designs to examine their competence. More than one program was required for the modelling work so that the designed rear underrun protective devices could be done precisely. Solid modelling was made with the SolidWorks software, the finite element meshing was created with the ANSYS finite element analysis program, boundary conditions, material properties and connection definitions were made using the LS Pre-Post program. The vehicle model used in the literature was used to simulate the behaviour of the designed rear underrun protection device model in the dynamic environment and the vehicle was hit at a certain speed. This simulation was performed with the 3D non-linear finite element analysis program LS DYNA. As a result of simulation, speed and acceleration of rear underrun protection device and vehicle data are collected. Acceleration values obtained in the X, Y and Z directions were evaluated using the program called TRAP, which calculated the ASI, and evaluated the adequacy of the rear underrun in terms of the simulation results.