Dynamic failure of annealed and chemically strengthened glass under compression loading

The goal of this article is to explore the dynamic mechanical behavior of annealed and chemically strengthened glass used in transparent laminated structures for buildings, armor and aerospace applications. Static compression (SC) tests were first conducted using the universal testing machine followed by dynamic compression (DC) tests at an average strain rate of 650 s⁻¹ and 350 s⁻¹ using modified Split Hopkinson pressure bar (SHPB) for annealed and strengthened glass, respectively. In DC tests, high-speed photography and flashlights were made synchronous with a loading pulse to spot the damage/crack initiation, propagation, and fracture process in both types of glasses. Static tests data concerning the compressive strength revealed that annealed glass (AG) showed strain rate sensitivity, in contrast to this chemically strengthened glass (CSG) showed no substantial strain-rate sensitivity. In DC tests compared to SC tests, it was found that both types of glass are rate sensitive and compressive strength remarkably increased at high strain-rate loading. The glass fracture process for both AG & CSG is also analyzed through high-speed imagery recorded during DC tests. The crack initiation, propagation, and glass debris are also discussed to explicate the failure mechanism of glass specimens.