Numerical analysis of dynamic responses of laminated glass window subjected to gas explosions

Abstract

Gas explosion is one of the main forms of accidental explosions that may cause significant loss of lives and economy. However, the researches on the dynamic responses of structures or structural members under gas explosion are still very limited. The current analysis and design approaches of structures against accidental gas explosions specified in design guides are mainly based on equivalent methods to predict loads from gas explosions, which may not necessarily give accurate explosion loads predictions and hence structural response estimations. Since the flying fragments from damaged architectural glass windows and façades induced by gas explosions are one of the main reasons to cause injuries in such an event, it is essential to accurately predict the damage and dynamic response of architectural glass structures subjected to gas explosion load for developing effective technology to mitigate the hazard from gas explosions. In this paper, the dynamic responses and failure modes of laminated glass window under TNT and gas explosions are firstly simulated with the validated numerical model, and the results are compared and analyzed. The results show that the laminated glass window under gas explosions experience typical bending failure, which is different from the case of laminated glass window under TNT explosions, implying the TNT equivalence method normally used to predict the blast loads for structural design against gas explosions may not lead to reliable predictions. To quantitatively demonstrate the differences, blast loads recorded in three gas explosion scenarios and the corresponding blast loads estimated by the TNT equivalence method are used to predict the dynamic response and damage of laminated glass windows. It is found that the TNT equivalence method for predicting gas explosion load in a vented room, in a partially confined chamber and in free field lead to over predictions of the responses of the laminated glass window. Parametric studies are also carried out to explore the influences of some key parameters, i.e., window size, glass panel thickness, interlayer thickness and boundary conditions on the response of laminated glass window subjected to gas explosion. The results indicate that increasing the glass and interlayer thickness, increasing the ratio of length to width of the laminated glass window, and adopting soft support constraints could greatly reduce dynamic responses and damage of the laminated glass window subjected to gas explosions.