Finite element simulation of brittle fracture of bulletproof glass system

The thickness and weight of a bulletproof glass material can be reduced by using strengthened glass that possesses current protective capabilities. In this study, numerical simulations are performed to estimate the protective capability of strengthened borosilicate glass used in bulletproof glass systems. High-velocity impacts and perforation behavior are well described by a dynamic brittle fracture model. A parametric study of the material model of glass is conducted by comparing test results of individual impacts with corresponding numerical estimations; the size of back-surface spall, morphology of perforated surface, and fractured areas are compared. Material parameters of strengthened and non-strengthened borosilicate glasses are determined. Numerical simulations that use a material model considering these parameters well describe the overall fracture behavior of bulletproof glass. The main parameters that affect protective capability are initial compressive yield and fracture stresses. The protective capability of strengthened borosilicate glass is ∼20% better than that of non-strengthened borosilicate glass.