Mechanical behaviours of aeronautical inorganic glass at different strain rates

By using an electronic universal testing machine and a modified split Hopkinson pressure bar device, the uniaxial compressive mechanical behaviours of glass used as the windshield of aircraft was tested. The experiments were finished at two quasi-static strain rates(4×10^-4, 4×10^-3s^-1) and two high strain rates(200, 400 s^-1). The glass fracture progress was also recorded by a high-speed camera. The experimental results show as follows. Catastrophic brittle failure was observed for the specimens tested at different strain rates. With the increase of strain rate, the compressive strength of the glass increases remarkably. By the fracture images and fragmentation forms, it is known that under compressive loads, the cracks initiate and propagate in the length direction under lateral tensile stress. Then the cracks connect and contact with each other, resulting in fragmentation of the specimen. The strain rate effect is explained properly in the point of microcrack initiation and development as well as energy dissipation.