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This article describes the application of the Friction Braced Frames (FBF) system for 4-and 10-storey buildings located in Vancouver, BC, in Canada. The FBF is coupled with a secondary moment resisting frame that provides back-up elastic stiffness and re-centring capacity that contribute to reduce storey drifts and more evenly distribute seismic energy dissipation over the frame height. In this study, the energy dissipation components consist of Pall friction devices and the system was designed using a conventional force-based method. The moment frame was proportioned to remain essentially elastic under the design seismic displacements. The seismic response of the system is examined through nonlinear response history dynamic analysis. An exhaustive test program was developed to verify the capacity of the system to sustain the anticipated seismic demand. Full-scale testing was performed on brace sub-assemblages and individual brace specimens equipped with friction elements. The experimental program included full-scale dynamic testing under real-time seismic displacement histories as obtained from response history analysis. The numerical simulations and test program showed that the dual FBF system represents an effective system for enhanced seismic response of multi-storey building applications in high seismic regions.

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In the theoretical or numerical analysis of composite/hybrid structures, headed stud connectors at the steel–concrete interface are usually modelled as linear spring elements; thus, their tensile stiffness will be an essential parameter to affect the tensile force distribution. This article investigates the tensile stiffness of headed stud connectors through theoretical analysis combined with the existing pull-out test results. The pull-out displacement of headed stud connectors from concrete blocks mainly includes two parts: one part is the elastic elongation of the stud rod and another is the axial displacement of the stud head in concrete blocks resulted from the concrete elastic deformation. Mindlin’s solution is employed to predict the second part displacement with the introduction of an unknown coefficient, which is estimated based on the existing headed anchor pull-out test results. Subsequently, an equation for predicting the tensile stiffness of headed stud connectors is proposed. The predicting tensile stiffness for headed stud connectors with various stud heights presents a good agreement with the pull-out test results. Meanwhile, neglecting the axial displacement of the stud head in concrete blocks, especially for relatively short height headed studs, will produce an overestimated tensile stiffness.