Seismic response of joints for steel elevators

The continuous increase in world population and the consequent growth of urban density is driving the construction of increasingly taller buildings. In this context, elevator systems play a crucial role in ensuring the functionality, accessibility and serviceability of high-rise structures. Consequently, engineers are increasingly focused on the development of safe, efficient and cost-effective steel structural systems for elevator support frames. To satisfy both structural and economic requirements, thin-walled steel members are often adopted, as they provide adequate mechanical performance while limiting material consumption and overall weight. The paper presents an experimental–numerical investigation on the monotonic and cyclic response of bolted beam-to-upright joints used in steel skeleton frames for elevator systems. The monotonic behaviour of the joints is first analysed, since it provides the reference information required to define the loading protocol for the subsequent cyclic tests. The cyclic response is then discussed for four joint configurations, obtained by combining two different upright cross-sections and two beam cross-sections. Finally, finite element models are developed and calibrated against the experimental results. The validated numerical models are then used to assess the joint response and to identify possible design improvements aimed at increasing both resistance and stiffness.