GNGTS 2022 - Atti del 40° Convegno Nazionale

GNGTS 2022 Sessione 2.2 305 FRAGILITY ASSESSMENT OF GLASS COMPONENTS BY SINGLE-DEGREE OF FREEDOM APPROXIMATION S. Mattei, C. Bedon University of Trieste, Department of Engineering and Architecture, Trieste, Italy Introduction . In the last decades, the design of structural elements is increasingly winking to systems characterized by unconventional materials, or rather to elements not commonly used for the construction practice of the country to which it refers. These materials, such as structural glass (Haldimann et al. , 2008), pultruded profiles, etc, are gradually making their way into the construction market, sometimes used in combination with other commonly used materials to offer better characteristics, such as fibre-reinforced concretes. Although glass has been used for hundreds of years in the construction of buildings, it has always played a secondary role, to which no load-bearing capacity is entrusted. Generally, glass elements are used in practical construction to bring light to the structures, improving their aesthetics and sustainability taking into account the low impact that has on the environment. Moreover, the consideration of the contribution of glass curtain walls in the structural dynamic response has been highly recommended due to its significant influence on the lateral resistance. However, within the performance-based earthquake engineering framework the estimation of expected losses is an aspect that must not be overlooked, since the observed damage of this type of elements during a seismic event leads to a lowering of the performance level of the entire building (Karavasilis T.L. and Seo C.Y., 2011), such as in the case of masonry infill walls in RC buildings. An efficient method to quantitively address the seismic structural vulnerability is related to the generation of fragility curves designed ad hoc for the single system components in order to combine the dynamic response of structural and non-structural elements (Bianchi et al. , 2019). However, the derivation of these curves involves the use of methods which, although a reliable result is provided, require a large amount of uncertainties to be included and a very high computational burden (Zentner et al. , 2017). Therefore, this work aims to provide an application of theoretical methodology that can simplify the seismic response evaluation of glass systems. In detail, the paper presents and discusses seismic fragility assessment of glass systems by using the equivalent Linear Single- Degree-of-Freedom (SDOF) and Non-Linear SDOF calibrated on pushover analyses obtained for FE models in ABAQUS/CAE. The structural response is also compared to that of the numerical non-linear dynamic analyses performed on a three-dimensional structural model. Background on fragility assessment of glass systems. Fragility function, in a simplified sense, is described as the probability of exceeding a limit value of the damage state for a specific seismic intensity: (1) Where the subscript i denotes the damage state threshold, EDP corresponds to the demand parameter, IM represents the intensity measure of the seismic event, Φ is the standard normal cumulative distribution function, θ and β are respectively the median and the logarithmic standard deviation of the data. In recent years several authors developed glass curtain wall fragility curves at different relevant damage states which are divided in serviceability or ultimate limit states. According to Porter et al. (2008), fragility curves may be derived by various methods, based on analytical,