1990 Geo Prism front door side tempered glass windows 3 mm thick were slowly bent, or shock loaded, to failure, with the glass clusters and fragments then found as large as 13 x 10 cm, weight to 42 grams, with some sharp points and slivers, and speed of release from the glazing surface of intermediate size pieces to 23 km/h. The fracture patterns of the tempered glass bent or shock loaded to failure were often oblique rather than perpendicular, in comparison to the patterns of an unloaded tempered glass broken by a locally applied sharp pointed object. This explains the sharpness and many lacerations of tempered glass shattered in road crashes, often under conditions of bending or shock loading of the edges of the glazing before it fails. Modification of Federal Motor Vehicle Safety Standard (FMVSS) 205 to include fragment studies and laceration effects is suggested. (A) See also IRRD 893301.
Abstract