Abstract

Destructive testing of commercial automotive movable laminated side glass was conducted to document the occupant retention characteristics of this glazing system in quarter-roll crashes with a prolonged slide distance. That is, in some overturns a vehicle will slide to a halt on its side with a window adjacent both to an occupant’s position and to the moving roadway. It is known by field experience that this situation can result in injurious ejection of the occupant through the adjacent window if the window is constructed of tempered glass and the window has fractured. When tempered glass fractures, the window disintegrates and fully opens the portal. With the laminated side glazing that is used on some passenger vehicles, fracture of the inboard and outboard glass plies will not necessarily cause the “sandwiched” PVB interlayer to be compromised. This PVB interlayer allows the glass plies to remain in place and resist the sliding interaction. This diminishes the ejection hazard that is associated with tempered side glass. The three drag tests described within this technical paper used a single model of sport utility vehicle driver’s position door and factory installed laminated side door glass. The testing replicated the interaction of the exterior surface of the laminated glass against the moving roadway while the glazing was pre-fractured and the interior glass ply was subjected to significant simulated occupant loading. These conditions ensured contact of the exterior glass ply against the moving abrasive roadway. The detached and slightly modified driver’s door was pulled at near highway speed over a substantial distance against abrasive asphalt, simulating a rollover accident with the side of the vehicle sliding to halt. The results of these tests show that the exterior surface of the glazing, primarily consisting of the hard ceramic SiO2, is sufficiently wear resistant and durable to wear but not rupture or pull out of the peripheral channel. This testing shows that laminated glass is the superior glazing material for this accident mode from an occupant containment perspective.

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