Shake table tests of three storey cold-formed steel structures with strap-braced walls

Abstract

This study aims to increase the knowledge of the seismic behaviour of low-to-medium rise structures, in which the seismic force-resisting system is provided by cold-formed steel strap-braced walls designed as non-energy-dissipating systems. The dynamic response of this system under seismic actions is analysed by performing shake table tests on two reduced-scale (1:3) three-storey two-bay prototypes, that differed in floor typology: steel–concrete floors (Type 1) or floors made of wood-based panels (Type 2). Main outcomes show that the seismic response can be considered as satisfactory, because the system seems to have inherent ductility even without a designated energy dissipating mechanism. In particular, the seismic response was approximately linear for tests having intensity not greater than that assumed for the design, whereas for tests having higher intensities the behaviour deviated from the linearity, with maximum interstorey drift angles greater than 2% without very extensive damage, and in-plane floor rigid behaviour for both prototypes according to the ASCE 7 definition.