@phdthesis{ShoushtarianMofrad2022, author = {Shoushtarian Mofrad, Ashkan}, title = {Evaluating bending and translational behavior of sandwich panels at ambient and elevated temperatures}, issn = {1611-5023}, doi = {10.26127/BTUOpen-5941}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-59410}, school = {BTU Cottbus - Senftenberg}, year = {2022}, abstract = {Steel cladding structures such as sandwich panels can replace bracing systems to provide further stability to individual structural members such as beams and columns. Previous researches studied the stabilizing effects of sandwich panels on the whole structure at ambient temperatures. It was shown that considerable savings could be achieved in the case of using steel cladding systems. In the STABFI (Steel Cladding Systems for Stabilisation of Steel Buildings in Fire) project, the primary objective was to study the stabilizing behavior of cladding systems in the fire. The current thesis is a part of the STABFI project focusing on the bending and translational stiffness of sandwich panels at ambient and elevated temperatures. The thesis consists of two separate parts, the bending and translational performance of sandwich panels at ambient and elevated temperatures. Sandwich panels are typically composites of two thin steel sheets and a core of higher thickness and lower density. They are valued for their excellent thermal properties. This research employs two different materials, including mineral wool (MW) and Polyisocyanurate (PIR), as a core. In the first part of the thesis, the bending tests carried out in Prague are described. The experimental results are presented in the first phase of this part. A finite element (FE) model is developed to validate simulations with experimental results, and then a comprehensive parametric study is carried out. During the parametric study, different factors such as panel thickness, width, span, the thickness of steel sheets, and the fire's influence on panels' mechanical behavior are investigated. Moreover, the analytical solutions obtained from Eurocodes (EN 14509, 2013) at ambient temperature are employed to predict the bending stiffness values. The analytical solutions are then developed to apply at elevated temperatures by incorporating the reduction factors into the equations. Eventually, the accuracy of suggested analytical equations is compared with numerical results. In the second part of the thesis, after presenting the translational tests which also conducted in Prague and validation of FE models, an extensive parametric study on the decisive factors such as the steel sheet thicknesses, screw diameters and temperature effects on the sandwich panel connections behavior is performed. The parametric study shows how each parameter affects the shear resistance and stiffness of sandwich panel connections. Furthermore, the deterioration of shear performance at elevated temperatures is evaluated. The analytical solutions achieved from the ECCS manual are used to estimate the shear stiffness and resistance of connections at ambient temperatures. At elevated temperatures, the equations are developed to anticipate the abovementioned values in the fire case. Finally, the safety and accuracy of proposed analytical solutions are assessed.}, subject = {Sandwich panels; Finite element method; Fire; Resistance; Stiffness; Sandwichelemente; Finite-Elemente-Modell; Feuer; Widerstand; Steifigkeit; Sandwichbauweise; Stahl; Finite-Elemente-Methode; Steifigkeit; Biegung; Thermische Belastung}, language = {en} }