Smart Structures for Frontal Collision Mitigation 2002-01-0247

Frontal collisions represent the majority of real world crashes involving occupants with fatal or serious injuries. Conflicting requirements of the full and offset crashes impose a trade off between stiff structure to reduce intrusion and softer structures to prevent violating the G-limit of the passenger compartment. The fundamental constraint in this process is the plastic deformation properties of materials/structures, and the length of crumple zone available to the designer. This research seeks to extend the deformation properties of the frontal structure by introducing ‘hydraulic smart structures’ within the front part of the main longitudinal members. This allows the smart structure to increase its energy absorption capacity, change its deformation properties and adapt to varying collision conditions.

The ideal structure for frontal collisions needs to maximize the deformation zone, and adapt to impact conditions by stiffening at severe impacts and softening otherwise. Smart hydraulic structures are proposed to meet these ideal requirements. Sample “Hydraulic Smart Structures” were designed and tested for feasibility of crash under high pressure and high impact speed conditions. Full simulations of various scenarios of frontal head-on crashes were investigated. Significant reduction in the passenger compartment G-level as well as intrusion injury risk is expected with the integral use of “Smart structures” within the front part of the longitudinal members of the impacted vehicle (smart vehicle). The simulation investigations covered variation of crash severity in terms of mass, stiffness and speed of the impacting vehicle for full and offset crashes.