Stability analysis and design of double shear lap bolted connections in steel x-bracing systems

摘要

In this paper elastic and inelastic buckling analysis of the bolted double shear lap connections (DSL) are investigated, which are commonly used in concentrically braced steel frames comprised of cold-formed hollow structural section (HSS), as brace members. By the lack of any approach to evaluate the compression strength of a DSL connections, their design is usually relied on the tension load demand developed in the brace member. The results of quasi-static cyclic tests performed on six full-scaledX-bracing specimens have shown that the discontinuous brace member with DSL connection, not designed for compression, failed and fractured by the buckling at the connection. In all the specimens, the typical brace buckling only occurred in the continuous members, as expected. In this study. a simplified elastic stability analysis is employed to calculate elastic buckling load and effective length factor usable for the design of DSL connections. Anon-linear static analysis is also performed on a suggested numerical model comprised of beam-column elements to predict the response of the studied X-bracings, exhibiting the connection and member buckling. It is shown that the results of the both suggested design procedure based on the stability analysis and the numerical model agree well with the buckling load of the test specimens. It is also indicated that the slip of connection plates decreases the compression capacity and should be considered in the analysis and design procedures. (C) 2018 Elsevier Ltd. All rights reserved.