Effect of Sectional Geometric Parameters on Axial Impact Response of Hat-Section Beam

As the major part of the vehicle front side member, the hat-section beam structure's deformation mode and energy absorption characteristics under the axial impact is the main reference index in the design of automobile passive safety.In this study, we carried out a drop hammer axial impact test and numerical simulation with initial energy of 17.8 kJ for the hat-section beam with chamfering.In addition, keeping the total mass constant, we simulated two other beams with different sections of no chamfering and right-angle bend in the same conditions, aiming to investigate the influences of section geometric parameters on these characterizations as deformation modes, amount of deformation, energy absorption, peak load, the average crushing load and crushing force efficiency within a certain scope.The calculation results of the deformation modes and amount of deformation of the hat-section beam with chamfering are consistent with the experimental ones, verifying the rationality of the computation model.Due to the existence of chamfering in the structure, the pattern of structural deformation was transformed from a non-compact mode to a compact mode, the buffering effect was increased, whereas the maximum crushing load was reduced.When the bending angle changed from 93° to 90°, it only has minor influence on the deformation mode, and the energy absorption of the beam with non-right-angle bending is better than that of the beam with right-angle bending.Therefore, the geometric parameters of the cross section have some influence on the deformation mode and energy absorption characteristics of the hat-section beam structure.