US Patent 8356857 Hood pedestrian energy absorber

An energy absorbing system includes a hood with inner and outer panels defining a rear edge cavity, and a pair of polymeric energy absorbers in the cavity. The hood and energy absorber are tuned to minimize an HIC value when a pedestrian's head contacts the hood during an impact to absorb energy prior to the hood bottoming out on the plenum of the vehicle. The energy absorber is preferably made of a polymeric material capable of withstanding high temperatures associated with going through a paint over or e-coat process, such as high temperature nylon. The illustrated energy absorber has a hat-shaped cross section and includes criss-crossing flanges tuned to provide an optimal force-deflection curve during impact.