Lateral-torsional buckling behaviour of long-span laminated glass beams: Analytical, experimental and numerical study

Highlights: • Successful assessment of lateral-torsional buckling (LTB) behaviour of 3-layer long-span laminated glass beam. • Good agreement between analytical expressions for LTB behavior and experimental and numerical results. • The susceptibility of laminated glass beams to LTB should be taken into account during the design stage. • Interlayers' viscoelasticity and thickness production tolerances considerably affect LTB and must be considered at design. This paper presents results of analytical, experimental and numerical studies on the lateral-torsional buckling (LTB) behaviour of long-span laminated glass beams. The analytical study was mainly focused (i) on the assessment of existing expressions for the determination of the effective flexural and torsional stiffness of 3-layer laminated glass beams and (ii) on the determination of the buckling resistance and post-buckling behaviour of long-span laminated glass beams taking into account the influence of changes in the thickness of the glass panes and of the viscoelastic properties of the interlayers. The experimental study comprised a flexural test of a simply supported and unbraced 8.20 m long PVB 3-layer laminated glass fin. Finally, three-dimensional numerical models were also developed in order to simulate the experiments and validate the analytical results. The results obtained show that the analytical formulae and the numerical tools available are able to accurately predict the LTB behaviour of long-span 3-layer laminated beams. The results also draw the attention to the importance of adequately considering the influence of possible thickness reductions on the glass panes and of temperature and loading time effects on the shear behaviour of PVB interlayers.