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.
The coefficient for the ploughing component of head-windshield friction is approximately 1 independent of the test conditions.