Mechanical properties of continuous adhesive glass-steel connections under monotonic and cyclic loading

Abstract

Structural sealant glazing systems (SSGS), currently also known as bonded glass, for facades originated over 50 years ago. Although a lot of new developments were introduced and essential experience was gained, the design of the continuous adhesive glass-metal connections used in conventional SSGS did not undergo significant changes ever since. To optimise the design of such connections and to enable the development of new and innovative concepts of adhesive connections in building construction, fundamental research on the structural performance of adhesive glass-metal connections is, therefore, inevitable. In this research, the focus lies on the mechanical behaviour of continuous adhesive glass-steel connections under cyclic loading to which these elements are subjected on a daily basis, e.g. wind, or possibly subjected during their lifetime, e.g. earthquakes. The aim was, by means of experimental testing, to compare the structural response of a continuous adhesive glass-cold-formed (stainless) steel connection using a conventional structural silicone under cyclic loading with the mechanical behaviour under monotonic loading. The experimental results revealed the presence of progressive cyclic softening in the continuous adhesive glass-steel connections. This can mainly be attributed to the appreciable change in mechanical properties of the structural silicone resulting from the maximum deformation value prior to cyclic loading, i.e. the Mullins effect. Based on the experimental results, a simplified analytical model was elaborated and (partially) validated. The effect of cyclic loading is an issue that has to be accounted for within further optimisation of glass-metal connections using rubber-like adhesives, e.g. structural silicones.