Windscreen study using a free moving headform : An investigation of windscreen behaviour when subjected to headform impact

Pedestrian protection performance becomes more and more in focus for the car manufactures and systems to reduce injury risk are under development. A wider understanding of both the present and the future windscreen performance in free moving headform testing is needed to optimize these systems. The purpose of this thesis was therefore to learn and understand windscreen behaviour when subjected to head impact and to gain knowledge of CAE status for head impact in windscreens from a pedestrian point of view. A literature review concluded that there are different ways to model a windscreen. It was found that the computer material models for laminated windscreen glass were not capable of fully representing the behaviour of this material under all impact conditions, particularly the non-linear behaviour after fracture or failure. Experimental testing on three different windscreen models, with a free moving headform in a horizontal impactor, has been performed. Test set up was according to Euro NCAP pedestrian testing protocol and three different windscreen angles were tested. The parameter investigated was curvature and HIC and deformation depth on the windscreen were used as evaluation tools. Deformation was measured with a laser positioned behind the windscreen at impact. Film analysis and integration of headform accelerations were used as comparison. The testing concludes that different curvature alone will not have a big influence on HIC and deformation. Keywords: PVB laminated windscreen, pedestrian, impact, free moving headfor