Blast resistance of laminated glass facades

Abstract

The aim of this thesis is to improve the understanding of the behaviour of Polyvinyl Butyral (PVB) laminated annealed glass façade panels subjected to blast loading. A full scale blast test was performed. During this, deflection and strain data were collected employing digital image correlation techniques (DIC). Local reaction forces were measured using several pairs of strain gauges on the support. The full field deflection and strain data obtained were in line with those observed in historical tests. The strain gauge data available showed that the reaction forces varied along the edge, with higher values being reached at the quarter length gauge locations. The results from this test and from other historical experiments were used to calculate the reaction forces along the entire perimeter of the glass pane. The results showed that the forces reach an early peak before the glass failure, and then rise gradually approaching a plateau at high central deflections. To explain the specific form of this force time history, the detailed behaviour of the laminated material after the glass skins failed was studied. Existing experimental data was employed to fit a material model to the PVB material. Two Prony series models with different hyperelastic springs and a model employing a full finite deformation viscoelastic law derivation were employed. It was found that the finite deformation viscoelastic model could represent the material’s behaviour more accurately and fully include its rate dependency. One of the PVB models was employed to study the delamination between the glass and the membrane. Delamination energies were found for different speeds of deformation, and these parameters were employed to study the delamination of samples presenting different crack arrangements. The results showed that these had only a limited influence on the behaviour of the composite.