No abstract

No abstract

Superelastic shape memory alloys (SMAs) have the potential to create a spontaneous recentering mechanism on the connections of a structural system under seismic actions, which results in mitigation of the damage in the main structural members. In this article, innovative types of steel beam-to-column moment connections incorporating SMA bolts and plates are introduced and studied through a numerical approach. First, SMA bolted end-plate connection model is produced and analyzed by means of the finite element method to validate the numerical analysis against the prior experimental results. Then, the performance of eleven different end-plate moment connection models subjected to cyclic loading is investigated. By selecting the lower values for the moment capacity based on bolts strength in comparison to the flexural resistance of the beam, the plastic hinge is transferred from the beam section to the beam-column interface. Hence, employing superelastic materials at the connection interface could be potentially effective in providing the desired self-centering effect in the connection. To this end, the impact of utilizing superelastic SMA bolts and end-plates instead of using the conventional structural steel on the overall cyclic response of the connections is evaluated in this study. Results show that extended end-plate connections equipped with SMA bolts and end-plates, if properly proportioned and detailed, not only exhibit a clear reduction in the residual drifts after a seismic event, but also can meet the ductility requirements with good energy dissipation and sufficient stiffness.

No abstract

No abstract

No abstract

No abstract

SUMMARY In the present article, the seismic performance of frames with reduced beam section (RBS) connections is evaluated. A key purpose of this study is the inclusion of connections flexibility in the seismic performance of RBS frames. Almost in every research projects carried out on seismic performance and design of RBS frames, the beam‐to‐column connection is typically assumed as fully rigid. The results of nonlinear finite element analysis performed on investigating the local performance of RBS connection reveal that they are within the American Institute of Steel Construction‐defined semirigid connections. Three building frames, including 4, 8 and 16 stories considering the semirigid connection as well as fully rigid connection, are considered. A numerical study of the overall seismic response of the building frames subjected to near as well as far field earthquake ground motions using nonlinear static and/or nonlinear dynamic analysis is presented. Results in terms of inter‐story drifts, total drifts, story shears and shear deformation in panel zone indicate that overlooking the flexibility of beam‐to‐column connections may lead to erroneous conclusions and unsafe seismic behavior that subsequently become significant in some cases. Copyright © 2012 John Wiley & Sons, Ltd.