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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.

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Design requirements for bomb blast protection are a challenge for façade engineers because of complex interaction of various elements with different mass and nonlinear stiffness. There are different mitigation techniques available depending on the hazard rating. Rigid protecting structures are neither accepted by architectural design demands, nor by occupants who do not want to be affected by obvious protection in daily life. As a result, smart blast enhanced façade solutions that cannot be distinguished from conventional facades are required, being capable of providing the required safety level. With introduction of dissipative façade brackets the dynamic analysis of the MDOF system of the façade can be balanced due to beneficial inertia effects. The dissipative bracket attracts the blast wave energy in lieu of the glazing, so that a switch of the typical load chain becomes possible. The probability that the glazing remains in uncracked state increases while the dissipative bracket dissipates the energy. In addition, the reaction to the primary structure can be mitigated. Finally, the anchor channel that connects the bracket to the concrete slab can be designed to stay in the elastic range. This reduces the refurbishment costs after a blast event. Experimental test results of different crash absorbing materials, dissipative brackets, and anchor channels are used for the development of combined design charts for the selection of adequate brackets and anchor channels.

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