A Comparison between the Single Plate and Angle Shear Connection
Performance under Fire
Serdar Selamet
1
and Maria E. Garlock
2
1
Graduate Student, Department of Civil and Environmental Engineering,
Engineering Quad, Room E209A, Princeton University, Princeton, NJ 08544 U.S.A.;
Phone: +1-609-258-5437, Fax: +1-609-258-1563; email:sselamet@princeton.edu
2
Assistant Professor, Department of Civil and Environmental Engineering, Princeton
University, Engineering Quad, Room E209A, Princeton University, Princeton, NJ
08544 U.S.A.; Phone: +1-609-258-2728, Fax: +1-609-258-1563;
email:mgarlock@princeton.edu
ABSTRACT
The strength and stability of connections in a floor system is an integral part of a
building structure. A connection is subjected to large compressive and tensile forces
during heating and cooling phase of a fire, respectively. Since shear connections are
only designed for gravity loads that produce shear, their behavior in a floor assembly
at elevated temperatures needs to be investigated. This paper compares the behavior
of three types of shear connections (single plate, single angle and double angle) under
fire conditions using the finite element software ABAQUS. The single plate shear
connection was validated by a full-scale building fire tested in Cardington. Adopting
Eurocode and AISC provisions on the shear connection design, the Cardington
connection was redesigned using the single and double angles. While the single plate
connections can provide substantial rotational ductility and tensile strength, it could
fail during cooling phase of a fire by bolt-hole bearing or bolt shear. The bolted
double angle connections are generally more ductile in tension which is advantageous
during cooling phase; however they are prone to develop prying forces which could
cause the failure of the bolts. In all of the connection models, the beam near the
connection experiences local buckling at elevated temperatures.
INTRODUCTION
Structural floor systems undergo significant geometric changes due to thermal
expansion of steel during a fire event. Additionally, the strength and stiffness of steel
reduce dramatically at elevated temperatures. Hence, connections become an integral
part of building construction because they could be subjected to large axial forces,
moments and strain reversal during cooling period of a fire [Ramli-Sulong et al
2007]. Current design codes [AISC 2005 and ECCS 2001] are based on isolated
member tests subjected to standard fire conditions. Such tests do not reflect the
behaviour of a complete building under either normal temperature or fire conditions
[Wald F. et al. 2006]. The complex interaction of structural components such as
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Structures Congress 2011
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