Abstract:

Multiple layered SentryGlas®Plus (SGP) laminated glass (LG) is increasingly adopted in the construction sector. The brittle failure of glass under impact leads to the sudden loss of load bearing capacity, however, limited data has been reported to date concerning the impact resistance of multiple layered SGP laminated glass. This paper reports an experimental investigation on the impact performance of triple layered SGP LG panels under hard body impact using a mean minimum breakage velocity (MMBV) test approach. Three categories of breakage sequence were classified by tracing the crack initiation with high speed photos. The impact resistance of SGP LG was calculated by examining the effects of factors such as breakage sequence, support conditions and glass make-ups. The LG panel with the clamped edges required higher MMBV to trigger the glass breakage and had an increase of 44% pre-breakage stiffness than that with the bolted connection. The evident improvement in post-breakage stiffness due to the beneficial crack pattern of heat strengthened (HS) glass, compared to its counterpart of fully tempered (FT) glass, was also revealed, however, the increase in MMBV is modest. The results also showed that a significant degradation of dynamic stiffness can be found in the post breakage stage. Two types of delamination were identified and the dependency of their delamination growth on the impact velocity was analyzed.

Key words: laminated glass, SGP laminated glass, structural glass, impact test, dynamic load