Comparison of different car front structures under nonaxial impacts

摘要

The design of the bumper beam, the energy absorbers and the front part of the longitudinal members and their connection defines the crashworthiness of the front structure of each car. The structure has to absorb energy for axial impact, offset impact but also for nonaxial impact configurations, which are investigated in this paper. For nonaxial impacts the energy absorbers and their connections have a large influence on the kind of deformation. Often front structures are deformed by global bending at impacts with large impact angles. A change of the connection between the bumper beam and the energy absorber from a swivel joint to a bending resistant connection can increase the capacity for nonaxial impacts. Analytical descriptions of the front structure regarding the kind of connection show the influence of the design parameters of the front structure on the critical impact angle. At the critical impact angle the deformation process changes from axial deformation to global bending deformation. A general analytical description is useful to understand the behaviour of the front structure for nonaxial impacts.