Numerical and analytical investigation on the dynamic buckling behavior of glass columns under blast

Current applications in buildings of structural glass elements often require design rules and formulations able to provide acceptable predictions for phenomena complex to describe, which generally depend on combination of several geometrical and mechanical aspects. The estimation of the buckling resistance of glass elements, for example, represents a topic of large interest for researchers, due to typical high slenderness ratios, limited tensile strength and brittle material behavior. In the paper, the buckling response of glass columns under impulsive orthogonal pressures (e.g. blast) and combined static compressive vertical loads (e.g. gravity loads or further service loads) is investigated. The dynamic buckling behavior of columns in out-of-plane bending is primarily analyzed. Advanced numerical nonlinear dynamic simulations are then performed on various laminated columns, by means of 3D numerical FE-models able to take into account the interaction of simultaneous loads and possible glass cracking. Analytical calculations are also carried-out by means of single-degree-of-freedom (SDOF) formulations derived from structural dynamics theories, in order to properly estimate blast and second-order effects on maximum deflections and corresponding tensile stresses. Finally, based on the rather good correlation generally found between numerical and analytical calculations, a design approach is proposed for practical estimation of buckling strength of glass elements in the analyzed loading and boundary conditions.