Flexural-torsional buckling behavior of eccentrically compressed laminated glass elements with 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.