Vol.:(0123456789) 1 3 International Journal of Steel Structures https://doi.org/10.1007/s13296-020-00352-2 Stressed Skin Design Versus Braced Frame Design Through Efcient Numerical Modelling Todor Vacev 1  · Andrija Zorić 1  · Miloš Milić 1  · Stepa Paunović 1  · Ivan Nešović 1 Received: 29 November 2019 / Accepted: 15 April 2020 © Korean Society of Steel Construction 2020 Abstract Steel frame structures are traditionally designed with bracings that stabilize the main bearing structure. Another approach is to apply the “stressed skin design” where the cladding structure takes the role of the bracings. In this research, the two approaches were analysed and compared in order to fnd advantages of any. A typical steel frame structure was chosen, and for the cladding, trapezoidal sheet metal was selected. Optional bracings were also considered. All static analyses were done using the fnite element method (FEM) and ANSYS Workbench software, including geometric and material nonlinearity. The structure was loaded perpendicularly to its gable, thus simulating typical wind action. Number of fasteners connecting the cladding and the frame is crucial for the “stressed skin design” concept, so this parameter was varied through the analysis. The stifness of the fastener devices was simulated in two ways: (1) simplifed, by merging of the adjacent nodes of the clad- ding and the frame, and (2) more accurately, using special joint elements with prescribed stifness. Obtained stresses and deformations were compared, and they showed obvious advantages of the “stressed skin design” over braced frame design, both in structural, and in economical aspect. In addition, important practical guidelines for the “stressed skin design” using FEM were proposed. Keywords Steel structures · Bracing · Stressed skin design · Corrugated sheet metal · FEM 1 Introduction Classic steel frame structures involve application of dif- ferent types of bracings whose purpose is to stabilize the main bearing structure in space, to maintain the designed geometry and shape, and to reduce the horizontal displace- ments of the slender elements. Alternatively, the “stressed skin design” stabilizes the frame structure due to the fact that wall and roof cladding possess signifcant in-plane stifness. Therefore, the cladding may accept and transfer horizontal forces acting on the building and provide spatial stability. However, application of this concept is not easy due to the complexity of determination of the stifness of diferent types of corrugated sheets used as a cladding, and to the difcult determination of the stifness of the connec- tions between the cladding and the bearing steel structure. This concept is covered only in general form by European standards (EUROCODE EN 1993-1-3 2006) and in recom- mendations for steel structure design (ECCS 1995). The research of the stressed skin behaviour of structures has a history lasting a few decades. The architects of the “stressed skin design” are E. R. Bryan and J. M. Davies from the University of Salford, Great Britain. They system- atized analytical methods in the book (Davies and Bryan 1982) and gave recommendations for “stressed skin design” of structures. Review of research in this feld, as well as design recommendations can be found in (Bryan and Davies 1975; Yiu 1987; Davies 2006; Dubina et al. 2012; Davies and Lawson 1978). This problem was also investigated experimentally, and feasibility of application of this concept was proven. Infuence of diferent cladding profles, fasten- ing device types and their gage was analysed (Mahendran 1997; Mahendran and Moor 1999; Xiaoguang et al. 2017; Wright and Hossain 1997; Wrzesien et al. 2015). Various authors proposed analytical solutions for application of the stressed skin design (Davies and Bryan 1982; Dubina et al. 2012; van den Bogaard 1987; Sokol 1996; Biegus 2015). Recently, numerical models for this design approach based on FEM were developed (Dubina et al. 1998; Duerr and Saal Online ISSN 2093-6311 Print ISSN 1598-2351 * Todor Vacev todor.vacev@gaf.ni.ac.rs 1 Faculty of Civil Engineering and Architecture, University of Niš, A. Medvedeva 14, Niš 18000, Serbia