An Evaluation of Laminated Side Window Glass Performance During Rollover 2007-01-0367
In this study, the occupant containment characteristics of automotive laminated safety glass in side window applications was evaluated through two full-scale, full-vehicle dolly rollover crash tests. The dolly rollover crash tests were performed on sport utility vehicles equipped with heat-strengthened laminated safety glass in the side windows in order to: (1) evaluate the capacity of laminated side window safety glass to contain unrestrained occupants during rollover, (2) analyze the kinematics associated with unrestrained occupants during glazing interaction and ejection, and (3) to identify laminated side window safety glass failure modes. Dolly rollovers were performed on a 1998 Ford Expedition and a 2004 Volvo XC90 at a nominal speed of 43 mph, with unbelted Hybrid II Anthropomorphic Test Devices (ATDs) positioned in the outboard seating positions. Vehicle dynamics, occupant kinematics, and glazing failure modes were evaluated through: on-board instrumentation, analysis of on-board and off-board high speed video and film, a survey of the evidence in the rollover debris field, and post-test inspection of the vehicle, ATDs, and glazing. Laminated side window safety glass did not prevent complete ejection of the ATDs. Five of the six ATDs in the Expedition were completely ejected from the vehicle, and 3 of the 4 ATDs were fully ejected in the XC90 test. Containment of the two ATDs that were not completely ejected was unrelated to glazing contact; the laminated window adjacent to each ATD vacated the window opening and both were partially ejected during the roll sequence. Side window glass fracture and failure was observed in association with ATD loading, ground contact deformation, and combinations thereof. On the basis of the performance observed in this study, it is concluded that heat-strengthened trilaminate glass is not a suitable candidate for occupant containment during rollover. Comparison of these full-scale rollover tests to prior laboratory-based evaluations of laminated side glass demonstrates that the prior studies fail to account for several aspects of the rollover environment, which contribute significantly to glazing loading, fracture, and failure.