Time-Temperature Dependency of Laminated Glass Subjected to Blast Load – A Numerical Study

The behavior of laminated glass has strong time-temperature dependency. Viscoelastic material models are often employed to define mechanical properties of Polyvinyl Butyral (PVB), the most common interlayer for structural glass applications. However, it is an apparent notion to simplify the high complexity of such material models, as only specific software is capable of considering this behavior. Most studies in blast design of laminated glass have focused on room temperature condition and recommend the use of elastic material models for PVB with high modulus of elasticity for simplification. The main purpose of this study is to develop an understanding of time and temperature dependency of interlayers in real building application. On the basis of empirical weather data, a range of interlayer temperatures is proposed to be considered for blast design situation in Germany for vertical double glazed and triple glazed units in accordance with Eurocode 0 and Eurocode 1. The results obtained from this analysis are further investigated within a transient structural parametric study of laminated glass to identify the effect of winter interlayer temperature and summer interlayer temperature in difference to simplified monolithic glass approach. As a result, significant increase of maximum principal glass stress and maximum deformation is observed for laminated glass subjected to blast load under summer temperature condition.