The technique of experimental stress analysis, i.e. bonded wire strain gauges and brittle coatings, were used to study the impact behaviour of glass bottles. The magnitude and distribution of impact stresses on both the inside and outside surfaces were determined, and typical impact breakage is discussed in terms of these stresses. Fracture diagnosis on bottles broken by impact correlates well with the observed stress patterns, and these patterns in turn provide a good basis for a detailed study of impact fractures. Duration of impact and dynamic behaviour of the bottles were studied with strain gauges and a cathode-ray oscilloscope. A typical impact takes the form of a single pulse of about 0.001-second duration and involves peak impact forces of the order of 1000bl.
