Effect of material type, stacking sequence and impact location on the pedestrian head injury in collisions

• Investigation of material type and stacking sequence of hood skin on head injury.
• Investigation of different spots of the hood in a head-hood collision.
• Effect of hood thickness on hood-head impact.

In this study, the effect of engine hood material type (aluminum, steel, carbon fiber epoxy CF/EP and glass fiber epoxy GF/EP composites) has been investigated on the pedestrian head injury in a collision (HIC). Child and adult Finite Element head models have been implemented for the simulations. In the models made of composite materials, effect of different stacking sequences has been investigated and four different 8-layered non-crimped fiber (NCF) composites with the stacking sequences of [0]8, [90]8, [0/90/0/90]s and [−45/0/45/90]s have considered. It was seen that using CF/EP composite instead of steel decreases the HIC value and hood weight by 42.6% and 46.8%, respectively. Moreover, [0]8 and [90]8 stacking sequences have the minimum and maximum HIC values among all the stacking sequences, respectively. Moreover, using composites made of glass fibers leads to higher HIC values with respect to those made of carbon fibers. In this study, the effect of location of head impact and hood thickness on HIC value for different hood material has also been investigated. For most of the locations, using composite materials led to lower HIC values. Increasing the skin thickness increases the HIC value for all the materials and its effect is more on steel, carbon-epoxy, glass-epoxy, and aluminum materials respectively. Increase in the hood thickness has higher effects on medial locations compared to lateral locations.