Seismic performance study on slipping bolted truss-to-column connections in modularized prefabricated steel structures

Abstract

This study proposed a new-type on-site all-bolted connection that connects a truss to a column and connects a column to a column in modularized prefabricated multi-story and high-rise steel structures. The components in a module are welded together in the factory, and various modules are assembled together quickly using the proposed connection on site. The connection connects a truss to a column through cover plates that extend from the flanges as well as through the vertical connecting plates and the joint flitches. The stiffness of the connection undergoes step-like changes as the load changes. During an earthquake, the cover plates slip relative to the chord members of the truss, dissipating energy. This study conducted tests and finite element analysis on the seismic performance of two specimens of the proposed bolted connection in which slip occurs between the cover plate and chord members, and some seismic performance data associated with the connection, such as hysteretic performance, skeleton curve, ductility, rotational capacity, stiffness degradation and failure mode, are obtained. Some parameters that affect mechanical and seismic properties of the connection were studied, and the slipping rule of the contact surfaces of the bolted connection was obtained. A comparative analysis of the test results for the slipping connection and the non-slipping connection shows that the slipping connection exhibited improved ductility and energy dissipation capacity without significantly reducing the ultimate bearing capacity, and most of the energy was dissipated from the slip. The proposed connection can be used for structures in seismic regions.