The LTB-behaviour of beams made of laminated glass

In many cases the lateral torsional buckling is governing the design of beams made of laminated glass. Then the question arises of how to consider the composite effect of the PVB-layers between the glass panels, which always shows a strong time- and temperature-dependant behaviour Also the combination and sequence of permanent and variable load and temperature phenomena plays an important rule for the prediction of the LTB-behaviour, as these effects have significant influence on the stability load capacity of laminated glass. In the following paper the most important steps for the solution of a new developed design concept [1] are presented, by which the complex time dependant LTB-capacities of beams of laminated glass can be verified. On the basis of the experimentally obtained time- and temperature dependant stiffness-behaviour of the interlayer the load capacities of these beams can analytically be predicted. Comparisons with large scale tests and simulations show good agreements with the results. Finally the design procedure is able to take into account also sequence effects due to variable loads as well as temperature.