Dynamic response of glass under low-velocity impact and high strain-rate compression loading

In this research, the dynamic response and energy absorption characteristics of four different types of commercially available glass have been investigated experimentally. Soda Lime, Starphire, Borosilicate, and Fused Silica were characterized using a Dynatup 8250 drop weight impact test system, and a modified Split Hopkinson Pressure Bar (SHPB). In the low-velocity punch-shear experiment, similar trend has been observed for all glass types, and Starphire and Borosilicate demonstrated the highest total energy absorption. High strain-rate SHPB compression tests were carried out on cylindrical glass samples at two different strain-rates. Borosilicate shohigher compressive strength and energy absorption in comparison to the other glass types. The results indicated high dependency of compressive strength, failure strain, and specific energy absorption to strain-rate, in all four types of glass. Also, Borosilicate glass specimens with three different polished surfaces were tested to study the effects of surface polishing on their dynamic compression behavior. A marked improvement has been observed in specimens with less surface flaws. A high-speed camera was also utilized (at 500,000 fps) to study the crack propagation and failure mechanism during the SHPB event. Brazilian disk indirect tensile tests were attempted on glass samples using a modified SHPB system. A high-speed video camera and Laser Occluding Expansion Gage (LOEG) system were used to measure the deformation in cylindrical glass specimens. Due to the brittle nature of the glass and equipment/instrumentation limitations, the low level of strain could not been detected