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This paper presents a numerical simulation aimed at analysing the seismic performance of low- and mid-rise cold-formed steel (CFS) framed buildings, employing wood-sheathed shear wall panels (SWPs), designed according to a seismic design procedure compatible with the framework of the Eurocodes. To simulate their nonlinear behaviour, the structures were modelled adopting a recently developed deteriorating hysteresis model. In order to study the seismic performance and determine the seismic performance factors, Incremental Dynamic Analysis of 54 archetype buildings was performed in OpenSees. The seismic performance assessment was evaluated according to the methodology defined in FEMA P695. The results indicate that a behaviour factor q equal to 2 is appropriate for CFS framed structures using wood-sheathed SWPs lateral load resisting system designed for low and moderate seismicity regions. Further, the probabilistic seismic risk assessment of the studied frames, is presented. The importance and usefulness of the risk metrics are highlighted and adopted as an indicator to explore the behavioural features of the CFS-SWP structural system. Overall, the assessment procedure showed an acceptable seismic performance and therefore the CFS-SWP can be seen as a reliable structural solution to achieve performance-based objectives even in moderate-to-high seismicity regions.

This paper focuses on the characterization of the behaviour of Concrete Filled Steel Tubular (CFST) columns made with Rubberized Concrete (RuC), and on the development of an accurate numerical model for the simulation of CFST columns under monotonic and cyclic bending. The test campaign involves 18 CFST specimens with different configurations, namely the cross-section slenderness, the concrete strength, the axial load level and the lateral loading type. All CFST members tested exhibited good ductility under monotonic loading. The Eurocode 4 design provisions was verified against the test results and the design capacities of the CFST members were validated to be conservative. A comprehensive 3D Finite Element (FE) model was developed and calibrated based on test results. The FE model proved to be reliable in predicting the bending behaviour of CFST member, in terms of local buckling deformation modes, ultimate capacity and ductility of the CFST columns.

Steel moment-resisting frames (MRFs) are well known for their ductile and stable hysteretic behaviour. For this reason, they are an attractive and effective structural system for seismic resistance. Current seismic design codes, namely Eurocode 8, provide system performance factors that should be used in the seismic design under different ductility classes. However, recent research studies have shown that the use of the code-prescribed performance factors lead to stiffer and heavier structural solutions that are not consistent with the performance-based design assumptions. A new methodology, Improved Force-Based Design (IFBD), has recently been proposed with the aim of a more rational determination of the adopted value of the behaviour factor, q, instead of using the upper bound reference values provided by the design code. This paper investigates if the obtained values of q for both EC8 and IFBD concerning steel MRFs are not only adequate, but also provide sufficient margins against collapse under maximum considered earthquake (MCE) ground motions. To this end, the methodology proposed in FEMA P695 was used. Additionally, the expected direct economic seismic losses are computed according to the PEER-PBEE methodology.