Although relevant information regarding the curtain walls structural damage state is available, hardly any data referring to the seismic loading effect on the overall façade performance is found in the literature. The present research attempts to assess the unitised curtain walls seismic performance by identifying the occurring damage mechanisms based on full-scale testing and finite element modelling.
The study initiates with a state-of-the-art discussing in detail the relevant research areas. Additionally, an introduction to the curtain wall numerical modelling field is provided. This literature review originates both from full-scale experimental testing and findings of academically developed finite element models. The case study of an experimental procedure is also described accompanied by the curtain wall response to the inter-storey drift implementation.
The modelling approach is introduced by presenting the mechanisms and the recreated curtain wall behaviour. Additionally, the process of identifying the properties of the curtain wall the boundary and loading conditions is displayed. The various modelling phases, the initial numerical development, its improvement through the calibration with the experimental results and the calibrated version, are also included.
The accomplishment of the first global curtain wall numerical model using DIANA FEA is a main research objective. The novelty consists in the exploration of the software possibilities and limitations which, although widely used for numerous applications, it hasn’t been utilised for façade numerical modelling. In general, the numerical representation of façade systems aims to provide a better insight of the curtain wall behaviour that will be eventually accurate to the extent that experimental tests won’t be needed for their validation.
Another interesting area is the correlation of the numerical behaviour to the experimental results measured on the curtain wall mock-ups while undergoing seismic loading. The model calibration intends for a realistic representation of the actual performance as recorded during the full-scale testing. Additionally, the contribution of structural silicone sealants in the system post-earthquake behaviour through the comparative performance of façade samples with dry gasket and systems with structural silicone is assessed. This evaluation aims to reinforce the knowledge regarding the strengths and weaknesses of wet and dry configurations and to indicate their appropriate application.
The research attempts to contribute to the seismic risk assessment of unitised curtain walls by identifying the governing failure mechanisms. This evaluation is performed with regards to the silicone sealant, simulating both dry and wet configurations. Thus, a sensitivity analysis varying over the structural silicone bite is developed with respect to the façade ultimate failure. The curtain wall overall response is addressed by evaluating several parameters (displacements, distortion, rotation and maximum stress per component). Moreover, the detection of the largest stress values occurring per element is used for the utilisation factors determination. This occurs by comparing the maximum stresses with the respective design values. The different outcomes provide the constructive context for further research of the façade response under seismic action. The study finalises with conclusions, considerations as well as suggestions for further research. Various challenges encountered are also introduced, aspiring to provide helpful information for future modellers.