Computational analysis of vehicle occupants dynamic response in side impact accidents with tempered glass in side windows replaced by laminated glazing

Abstract

Vehicle occupants involved in automobile side impact crashes are three times more likely to experience head injuries than occupants involved in frontal or other types of collisions. The most frequent contact source for an occupant in side impact crashes is the side window. In side impacts, failure of the side window glass affects the potential for the occupant head injury. Tempered glass in side window is easily shattered by exposing the occupant head into environment, where it can be directly impacted by the intruding or striking vehicle. In order to reduce the injury potential for occupant head in a collision, windows with laminated glass have been developed, which are gradually replacing the tempered glass. This study is mainly focused on understanding the dynamic response of the human head in side impact scenarios, when the tempered glass in the side windows is replaced with laminated glass. Quasi-static experiments are performed in this study with a free-motion headform impacting a laminated glass. The laminated glass is composed of two layers of glass separated by Polyvinyl Butyral (PVB) interlayer. A Finite Element (FE) model of the laminated glass window is created and impacted with the FE headform at the same velocity as in the experiment, and the model is validated against experimental results. The properties of validated glass model are implemented into the side windows of a small car model to determine the performance of laminated glass in a typical side impact scenario. The responses of the occupant with the tempered and laminated glazing with and without restraints are compared. Based on the performance of the laminated glazing in side impact scenario, the laminated glass has shown to reduce the possibility of failure of the glass and thus contains the occupant from ejecting with virtually no change in injury potential values.