Computational Method of the Stiffness Coefficients A and B in the Case of Frontal Impact from the Results of the Crash Tests

This study aims to develop a method for calculating stiffness coefficients A and B of the Computer Reconstruction of Automobile Speeds on the Highway (CRASH) algorithm in the case of the frontal impact based on the crash test experiments of the National Highway Traffic Safety Administration (NHTSA). For this purpose, we used two crash reports of Hyundai Sonata GLS 4-Doors Sedan model 2011 to calculate the coefficients A and B accurately and find a relationship between them. Thereafter, to verify the relationship between the coefficients A and B, we selected randomly from NHTSA’s database a set of 198 vehicles produced by seven manufacturers between 2003 and 2020 and calculated these coefficients using the computational method suggested in the literature. The crash speeds determined based on these coefficients showed a low correlation with the measured crash speeds obtained during the crash test of the vehicles.However, for the same sample of vehicles, we used the relation found previously to calculate the coefficients A and B, the speeds calculated using these coefficients are perfectly correlated with the impact speeds measured experimentally, we thus conclude that the ratio between the two stiffness coefficients A and B is always equal to 12.512 m regardless of the type of vehicle. This finding will make it possible to simplify the calculation of the energy absorbed in the frontal impacts by the reduction of the two coefficients of stiffness in only one coefficient at the same time as improving the precision of our calculations of kinematic reconstitution.