An investigation of compatibility for the passenger car fleet in head-on frontal collisions

Vehicle crash safety is an important field in vehicle design. There are customer-oriented or regulatory vehicle crash tests made to measure the crash safety of vehicles. In the frontal crash tests conducted by the US National Highway Traffic Safety Administration (NHTSA), vehicles hit the full-width rigid barrier (FWRB) at constant speed (56 km/h) and the safety levels of the vehicles are measured with the data obtained with the help of sensors. Although these tests give an idea about vehicle safety, they cannot fully test real-world collisions due to the problem called incompatibility. For this reason, in this thesis, the incompatibility problem is investigated by modeling head-on frontal collisions. For this purpose, 52 vehicles with different characteristics produced between 2011 and 2018 are selected among the vehicle crash test data available on NHTSA's website. The loading and unloading stiffnesses of the front structural elements of these vehicles are estimated with a linear approximation, then a lumped-mass model is constructed for frontal head-on collisions and all possible collisions of the selected vehicles are simulated with the help of a computer software. By comparing these data with the full-width rigid barrier (FWRB) frontal impact tests, it is aimed to have an idea about the level of the incompatibility problem between vehicles. Thanks to the model used in this study, the necessary data for the initial design of vehicle safety systems can be easily obtained with a cheaper solution than real crash tests, and different test conditions can be easily tested in the computer environment.