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A test program was conducted to characterize the impact response of an experimental 2-ply windshield construction with a polyurethane (PUR) plastic inner layer. Windshield impact tests were conducted using a linear impactor test facility. Principle among the findings was that the impact response of prototype PUR 2-ply windshields does not differ that significantly from that of baseline 3-ply HPR (High Penetration Resistance) windshields for the subcompact vehicle geometry tested. However, the impact responses of both PUR 2-ply and 3-ply HPR subcompact vehicle windshields were found to be highly variable. Average performance of either construction could thus be enhanced if ways could be found (and then implemented) to reduce this variability.

A test program was conducted to characterize the impact response of an experimental 2-ply windshield construction with a polyvinyl butyral / polyester (PVB/PET) inner plastic laminate. Windshield impact tests were conducted using a linear impactor test facility. Principal among the findings was that the measured impact response of prototype PVB/PET 2-ply windshields was highly variable. Average performance of this construction could thus be improved if ways could be found (and then implemented) to reduce this variability.

A laboratory sled test program was conducted to evaluate the effects of a lubricant on the inner surface of a windshield on occupant injury criteria and facial lacerations. These (5) tests simulated 19 km/h barrier impacts of a production vehicle with 2.29 - 0.95 - 2.29 mm windshield laminates. The lubricant in these tests was a 60,000 centistoke (0.06 m2/s) silicone fluid which was manually applied to the windshield prior to sled acceleration. Laceration levels were evaluated in terms of the number, length, and depth of cuts produced in the double-layer chamois skin head coverings on unbelted Hybrid III dummies. Laceration levels were reduced by two orders of magnitude from those experienced with uncoated windshields, though performance did not reach the zero laceration levels sometimes attained with Libby-Owens-Ford (LOF) and Securiflex laceration shield windshield treatments.

The purpose of this work was to measure on-road the objective and subjective changes in vehicle interior noise due both to changing from the current 3-ply windshield construction to an experimental 2-ply windshield and to changing the thickness of the single glass ply in the 2-ply construction. Measurements and subjective ratings of interior noise were made under a variety of test conditions in two nominally identical vehicles. One vehicle served as the “baseline” vehicle, while the other vehicle contained the particular windshield under test. Test conditions were chosen to study how the interior noise due to the intrusion of traffic noise, engine noise, road noise, windrush noise, raindrop noise, and wiper blade-on-windshield noise was changed by the various windshields. A jury of test subjects rated the interior noise on a 10-point scale in both front and rear seat positions in back-to-back rides in the two vehicles.

An experimental program to characterize the impact response of a standard 3-ply high penetration resistance (HPR) windshield was conducted using a specially designed linear impactor test facility (1). * Parameters varied included the location and angle of impact, impactor mass and velocity, windshield bonding system, and windshield integrity (whether it was pre-cracked). Specific findings included the following: The magnitude of the initial spike in the force-time history is a function of the inertia of the windshield mass localized around the impact site. The windshield bond has no effect on this initial force spike and thus cannot be used to alter or control it. Minor pre-cracking of the windshield has no effect on the impact event. The impact severity decreases as the rake angle (mounting angle with respect to the vertical) increases. The location of the initial impact site has only a minor effect on the impact severity.

An experimental program was conducted which demonstrated that a 2-ply windshield could be constructed with impact performance, as measured in the laboratory, comparable to that of standard 3-ply HPR windshields with inner Shield and Securiflex laceration shield treatments. The 2-ply windshield construction chosen for testing contained an outer ply of float glass and an inner multilayer laceration shield. This laceration shield is comprised of a polyvinyl butyral interlayer (0.95 mm thick), a polyester “laceration shield” (0.13 mm thick), and a proprietary abrasion-resistant coating (these three materials being produced by Du Pont). Full-scale sled tests were performed of the 2-ply construction using unrestrained Hybrid III dummies at the Safety Research and Development Laboratory (SRDL), GM Milford Proving Ground.