2021 Volume 70 Issue 12 Pages 918-925
Safety glass, such as general laminated glass and glass/polycarbonate(G/PC) laminated safety glass, is used in the viewing ports of machine tools. G/PC laminated safety glass meets the requirements for being used as a viewing port and has good impact resistance, solvent resistance, abrasion resistance, and transparency; however, its impact fracture behavior is unclear. In this study, we investigated impact fracture behavior of G/PC laminated safety glass experimentally and analytically. Specimens of G/PC laminated safety glass with different interlayer and PC thicknesses were tested under different impact energies using a drop weight test machine. Moreover, finite element analysis (FEA) model of the G/PC laminated safety glass was carried out considering the drop weight test, using explicit FEA code LS-DYNA. Storage modulus measurements obtained from dynamic mechanical analyses was applied to the interlayer in the FEA model. Results showed that the critical impact energy increased when PC thickness increased due to the drop weight test. As the interlayer thickness increased, the critical impact energy increased, at a constant PC thickness. The glass was also damaged radially and circumferentially by the impactor; the damaged state differed depending on the structure of the G/PC laminated safety glass. According to FEA results, damage propagation of the glass changed from circumferential to radial as the PC thickness decreased. FEA results for features of impact fracture behavior of G/PC laminated safety glass were also compared qualitatively with experimental results.
