Seismic design of light gauge steel framed buildings: Final report

Seismic design methods for light gauge steel framed buildings have been developed in this project. The scope of the project was limited to one- or two-storey buildings with load-bearing stud walls made of cold-formed steel profiles. The proposed methods are directly applicable in low seismicity areas defined in Eurocode 8, but can also be utilised in higher seismicity areas, it the structural applications with all details are verified by testing, for example, according to this document. Typical bracing methods that are also covered in this research are X-bracings with diagonal steel straps, sheeting of plane steel sheets or gypsum- or wood-based wallboards. The main strategy in the shear wall design is to design the bracing system as dissipative elements and design studs and tracks and other load-bearing elements to behave elastically with adequate overstrength. The research consisted of comprehensive connection test series for steel plate connections and test series for sub-assemblies for different shear wall corner configurations. Several shear wall tests were performed by using different bracing methods in order to find out hysteretic behaviour and other parameters needed in seismic design. One main goal of the project was to determine the Q factor for LGS structures. The Q factor takes into account non-linear behaviour of the structure and makes it possible to apply elastic design. Two hysteretic modelling alternatives for shear walls have been developed in the project. These models were used for parametric studies which allowed analytical formulae for calculating the Q factor to be acquired. Finally, design recommendations for seismic design of light gauge steel framed buildings were given for practical design.