Experimental and numerical full-scale investigation of a large triangular laminated insulating glass unit in bending under quasi-static loading

Large laminated insulating glass units (IGUs) with thin glass panes are increasingly used in lightweight structures, while experimental data under high uniform loads remain limited. This paper presents a case study on full-scale tests and nonlinear Finite Element (FE) simulations of large triangular IGUs subjected to quasi-static hydrostatic pressure. Three IGUs with an area of 4.26 m 2 and defined boundary conditions were tested to failure. Each unit consisted of two laminated panes of 6-mm-thick fully tempered glass with 1.52-mm-thick PVB interlayers and a 15-mm-thick cavity Water pressure, cavity pressure, pane deflections, and surface strains were measured. A nonlinear FE model including geometric nonlinearity, shear transfer, and load sharing between the panes was constructed and experimentally validated. The results show that nonlinear effects occur at relatively low load levels and become dominant with increasing deflection. At the maximum load, the average ultimate pressure was 74.5 kPa and the maximum deflection was 81 mm, corresponding to a deflection-to-thickness ratio of ∼ 6.8 based on the 12-mm total glass thickness of one laminated pane. At maximum load, the cavity pressure reached up to 45% of the applied load. The FE model predicted center deflections within ∼ 5% of the measured values and reached good overall stress agreement. The results indicate that linear approaches significantly underestimate the response of such large IGUs under increasing loads, highlighting the need for nonlinear FE analysis in similar configurations.