Seismic Performance of Glazed Curtain Walls. Connections: Experimental Testing and Finite Element Modelling

Abstract

Seismic events have shown the hazardous and expensive consequences resulting from seismic damage of non-structural elements. For this reason, the concern regarding the seismic performance of glazed curtain walls has acquired more relevance in the building industry; however, there is still a gap of information in the literature about this topic. To contribute with a broader panorama about the seismic performance of CW, this thesis project is focused on the seismic of the connections within a curtain wall.
This thesis intends to evaluate the performance of the connections that contribute to the seismic response of a glazed curtain wall with finite element models and experimental tests. To achieve this objective, several important points were taken into account. First, a literature study to understand what is a CW, and which are the components that may have influence in seismic design. Second, the two case-studies considered in this research are presented; in this section information about the specimens tested and types of tests performed is provided. Third, elaborate finite element models of the connections corresponding to each case study describing the criteria used. Finally, a comparison between the experimental and numerical results is elaborated to determine if the modelling approach is correct.
The experimental tests were carried out with the collaboration of Permasteelisa Group, and the numerical models were elaborated with DIANA FEA software. Five connections were analysed in this research: mullion to mullion, transom to starter sill, top aluminium bracket and hook, starter sill- bottom steel bracket, and silicone by a non-linear analysis with incremental displacements. At the end of this analysis it was observed a good agreement in the behaviour of the frame to frame connections with a minimal over estimation of the stiffness of certain frame to frame connections. Regarding the connections involving brackets, it was observed that the behaviour in the in-plane horizontal direction can be affected by the rotation of this elements because bolted connections shall be modelled as rotational springs. Finally about silicone it was observed that there exists a good match between the experimental results and the numerical models.
In conclusion, the modelling procedure was validated with experimental tests with relatively optimal results. Nonetheless, there are still limitations in the development of this topic that will be described in the recommendations but much more openness is expected in the future in terms of research on this topic.