Initial Stiffness of Reverse Channel Connections
2014 (English)In: Eurosteel 2014: 7th European Conference on Steel and Composite Structures, September 10-12, 2014, Naples, Italy / [ed] Raffaele Landolfo; Federico M. Mazzolani, Brussels: European Convention for Constructional Steelwork, ECCS , 2014Conference paper (Refereed)
The robustness of a structure in a fire situation greatly depends on the rotational capacity of the connection region. High rotational capacity is required at elevated temperatures since the steel beams lose their bending stiffness and exhibit increasingly large deflections under constant load. Beam deflections result in increasing rotations at the supports and may lead to collapse due to connection failure. The reverse channel has been proposed as a practical alternative to assemble beams to tubular columns. In a simple implementation, the bending moment generated in the joint due to rotation of the beam may be neglected; however, research efforts are being attempted to quantify the level of constraint. The typical arrangement of the connection type consists of a reverse channel with its flanges welded onto the face of concrete-filled tubular columns and the web bolted to the endplate of a beam. Thicknesses and depths of the reverse channel determine the level of rotational restraint at high temperature. The reverse channel has the ability to undergo catenary deformation in the tensile zone due to the applied rotation at the support and similarly it is relatively ductile in the compression zone. Overall, the reverse channel connection response is rather ductile in terms of its ability to undergo large rotational deformation as long as bolt failure is avoided through proper design.Various tests have been performed to study the behaviour of this type of connection such as full scale buildings, sub-frames, isolated joints and individual sections. The aim of these tests was to capture the connection behaviour in relation to other structural components in fire. This paper, however, focuses on the derivation and verification of analytical models to assess the initial stiffness of reverse channel/partial-depth endplate connections. The results from finite element analyses have been utilized to validate analytical models that describe the behaviour of this type of connection at ambient and elevated temperature. Insight into the analytical models provides proper background to a structural designer to estimate the initial stiffness and understand the behaviour of the reverse channel in the connection.
Place, publisher, year, edition, pages
Brussels: European Convention for Constructional Steelwork, ECCS , 2014.
Research subject Steel Structures
IdentifiersURN: urn:nbn:se:ltu:diva-37172Local ID: b1b2999c-51db-4152-a0a2-0106af2a8696ISBN: 9789291471218OAI: oai:DiVA.org:ltu-37172DiVA: diva2:1010670
European Conference on Steel and Composite Structures : 10/09/2014 - 12/09/2014
Godkänd; 2014; 20150304 (timhei)2016-10-032016-10-03Bibliographically approved