Influence of the lamination on the redundancy of a horizontally layered glass element and analysis of the debonding of the adhesive interlayer

It is now recognized that lamination enables to increase the redundancy of glass elements. This paper aims to quantify the possibilities of delamination between panes as well as the increase of redundancy for a horizontally layered glass element thanks to an analytical approach combined with a numerical modeling. From an analytical point of view, new procedures have been defined, taking into account the shear-lag effect as well as the mean curvature of the various adherents. The equilibrium of an infinitesimal element of the laminated structure has enabled to evaluate the interfacial stresses responsible for debonding phenomena. Based on this first approach and on the values of the interfacial stresses, a FE numerical simulation has been calibrated. This calibration is extended in two ways. First, the nonlinear behavior of the material is considered. A smeared crack approach is used to take into account the glass mechanical behavior. Then, a local debonding model involving the use of normal and shear springs is proposed at the interface between two glass panes. The mechanical behaviors of the springs are calibrated by simulating existing tension adhesion tests. Finally, by considering various structural cases, this work concludes that the debonding of the interface is a possibility and discusses its influence on the redundancy of the considered laminated structure.