Lateral Glazing Characterization Under Head Impact: Experimental and Numerical Investigation

In case of lateral impacts, the most frequent contact source is the side window. This window is also the most frequent aperture through which occupants are partially or fully ejected during a lateral crash. In order to keep occupant within the vehicle during a collision, laminated side glasses have been developed to gradually replace tempered glasses. Three-layered laminated glazing is composed of two glass layers separated by a plastic PolyVinylButyral (PVB) interlayer. The aim of the present work is to improve the understanding of the side window’s mechanical behaviour during a head impact. An experimental study is undertaken which consists of an impact of a Hybrid III dummy head on both laminated and tempered side glazing. It appears that at same velocity, impact against laminated glass leads to a significant lower injury head risk than a tempered glass. The principal role of laminated glazing has been preserved as PVB layer never fails. A laminated side glass FE model is then proposed based on experimental validation, with the PVB interlayer implemented by an elastoplastic law with failure criteria. A parametric study is carried out to define the influence of the laminated glass mechanical characteristics on the head response. The parametric study pointed out the importance of the glass layer thickness on head responses in terms of head injury criteria.