Spall strength of shock-loaded glass

The spall strength of soda lime glass was measured with Manganin stress gauges, in planar impact experiments, below and above the Hugoniot elastic limit of the glass. It was found that while in its elastic range the glass can withstand very large tensions (over 30 kbars), its spall strength reduced to zero when shocked just above the HEL. This confirms the assumption that the elastic limit marks the onset of fracture in glass upon shock loading.