Investigating the structural response of laminated glass plates under rigid body impact loads

Abstract

Laminated glass (LG) plays a vital role in impact-resistant glazing systems aimed at safeguarding against severe loads from events like hurricanes, windstorms, forced entries, air blasts, and ballistic threats. Nevertheless, our understanding of its resistance to perforation when struck by large rigid missiles is limited, as most research has centred on small missile impacts due to the high cost and complexity of full-scale large rigid body impact testing on LG. Although the response of laminated float glass to impact has been examined, much of this research has concentrated on static or quasi- static parameters. There has been limited exploration into how the rate of loading affects the prediction of LG’s impact resistance under dynamic scenarios. Currently, there are no established guidelines for evaluating LG’s resistance to rigid projectiles while considering the separate influences of projectile mass, impact velocity, and contact area. This research aims to fill these gaps by calibrating the Johnson-Holmquist Ceramic (JH-2) parameters for LG, utilizing a meta-analysis of existing studies to enhance the precision of impact simulations. A finite element (FE) model is developed to anticipate how LG panels with polyvinyl butyral (PVB) interlayers respond to large missile impacts. This model is validated using experimental data from the literature, carried out in accordance with ASTM standards. The study further develops the numerical model to create perforation vulnerability curves for LG panels based on 270 different impact scenarios. It reveals that increased interlayer thickness improves perforation resistance. Unlike earlier numerical analyses, this work incorporates silicone sealants between glass and aluminium frames, reducing peak stress by more than 90%, delaying stress peaks, redistributing the impact energy, and decreasing the number of cracks at panel edges. Furthermore, it identifies that impact momentum alone is insufficient to predict perforation resistance, emphasizing the separate effects of projectile mass, impact velocity, and projectile contact area. These findings contribute to a structured approach for assessing LG performance under high-strain impact conditions, closing the gap between theoretical and practical applications, and guiding the design of safer, more effective impact-resistant glazing systems.