Flexural and Torsional Buckling Behavior of Eccentrically Compressed Laminated Glass Elements with a Viscoelastic PVB Interlayer

Due to their typical high slenderness ratios, glass structural elements can be often subjected to buckling phenomena. Major difficulties in a correct estimation of their effective buckling strength and load-carrying behavior are generally given by a combination of multiple mechanical and geometrical aspects, especially in presence of laminated cross sections or interacting applied loads. In this paper, buckling experiments are performed on laminated glass beam-columns eccentrically compressed. Extended numerical and analytical comparisons are performed with test results in terms of Euler’s critical loads or load-displacement paths. As shown, appropriate calibration of numerical and analytical models generally can provide good agreement between buckling predictions and experimental results. Viscoelastic numerical models, in particular, if well-calibrated in terms of mechanical [e.g., creep effects in polyvinyl butyral (PVB)-foils] and geometrical properties (e.g., initial imperfections, load eccentricities) can provide interesting correlation with experiments, both in the form of global load-carrying behavior and ultimate loads. At the same time, simplified analytical methods based on the equivalent thickness concept can be used for rational analytical predictions—although in well-defined load-time and temperature conditions—and simplified buckling verification procedures.