Abstract

This paper presents an analytical model, developed for laminated glass subjected to a low-velocity impact. It has the ability to capture glass cracks as well as large non-linear deformations. It is based mathematically on the firstorder deformation concept, which considers the effect of membrane and transverse shear as well as bending. This theory uses damage mechanics to capture the glass cracking. For this purpose, several experiments have been carried out based on PVB laminated glass. The history of acceleration, transverse central displacement and velocity estimated over time is in a favourable relationship with the experimental information. In terms of laminated glass, non-dimensional coefficients have been suggested that regulate both the first peak contact force and the maximum transverse displacement. Laminated glass consists of several layers of soda-lime glass sheets bound together by intermediate layers of polyvinyl butyral (or PVB). Cracking of the glass layer is the main cause of laminated glass damage under both low and high-speed impacts. The main objective of the present article is to conduct experimental studies and numerical analyses of the glass ply cracking mechanism as part of the development of new strength parameters for PVB laminated glass. The non-linear characteristics of PVB are described using the Mooney-Rivlin constitutive model. The present article proves that it is possible to precisely model a wall made of VSG (Verbund Sicherheits Glas) laminated glass reinforced with a vinyl interlayer of appropriate thickness, and further, that such walls can constitute an element absorbing the impact energy of vehicles with specific parameters such as a passenger car, buses, and HGVs (Heavy Goods Vehicle). Based on the results of our study, new parameters were elaborated to determine the properties of PVB laminated glass exposed to vehicle impact. These new parameters were verified qualitatively by comparing the simulation results with experimental observations. We also assessed the strength of a wall of adequate thickness made of laminated glass at the ground floor level of a building exposed to a high-risk terrorist attack. The developed analytical model allows for a quick and reliable assessment during the initial design of safety glass, where a full-scale FE analysis is often too time-consuming.

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