Simple Shear Connections: Shear Tabs, Angles, and Coped Beams
Most beams in a steel building don't connect to their supports through a moment connection at all. A gravity beam framing into a column or a girder is usually attached through a connection specifically designed to transfer shear and essentially nothing else, deliberately flexible enough to rotate under load without developing meaningful end moment. That flexibility isn't a shortcut; it's the entire design intent, and getting it wrong in either direction, too stiff or improperly detailed, undermines assumptions made everywhere else in the analysis.
Why "Simple" Connections Need to Actually Be Simple
A beam analyzed as simply supported, pinned at both ends, is assumed to carry zero moment at its connections and all of its bending in the span between them. If the connection built in the field is stiffer than that assumption, restraining rotation more than the analysis accounted for, it starts attracting real moment it was never designed to resist, potentially overloading the connection's bolts or the column flange it attaches to. Simple shear connections are therefore detailed specifically to permit enough end rotation, on the order of the rotation a simply supported beam naturally develops under design load, that the connection stays flexible in practice and doesn't silently turn into an unintended moment connection.
Shear Tabs: A Single Plate Doing the Whole Job
A shear tab is a single steel plate welded to the supporting member's face and bolted to the beam web, and it's become the most common simple shear connection in modern steel construction largely because it requires only one set of field bolts rather than the two sets a double angle connection needs, cutting erection time meaningfully on a multi-story building with hundreds of beam connections. The plate's thickness and bolt pattern are sized for the beam's design shear reaction, but the plate also has to be thin and short enough, or specifically detailed as an "extended" shear tab, to accommodate the rotation the connection needs to remain simple rather than picking up unintended moment as the beam deflects under load.
Extended shear tabs, where the plate projects further from the support face than a conventional shear tab, are used specifically to accommodate erection tolerance and to provide the connection enough flexibility at longer beam spans, but extending the plate also changes the eccentricity between the bolt line and the weld line, a detail AISC's design guides address directly because getting that eccentricity wrong shifts real bending stress into a connection meant to see shear alone.
Double Angles and Single Angles: The Older, Still-Common Alternative
A double angle connection bolts or welds two angles to the beam web, one on each side, then bolts the outstanding legs to the supporting column or girder, providing a connection that's more tolerant of field misalignment than a single shear tab plate but requiring twice the bolting and, often, field welding on one leg if shop-welded angles are specified. Single angle connections trade some of that redundancy for simplicity and are common on lighter beams where the reduced capacity of a single angle leg is adequate for the shear demand.
Both angle types depend on the same rotational flexibility principle as shear tabs, achieved through bolt slip and angle leg bending rather than plate bending, and the specific capacity tables for standard angle and shear tab connections are published in the AISC Steel Construction Manual precisely so engineers can select a connection by beam reaction without re-deriving the bolt group and weld capacity from scratch on every beam, a companion to the moment connection detailing discussed in moment end-plate connections for the frames that do need full rotational rigidity.
Coped Beams Change the Shear Check at the Connection
Where a beam frames into a girder at the same top-of-steel elevation, the beam's top flange has to be cut away, or coped, to clear the girder's flange, and that coped section loses cross-sectional area exactly where the beam's end shear and any residual moment are highest. Coped beam webs are checked separately for block shear, a combined shear-and-tension tearout failure path through the bolt holes and the coped edge, a failure mode that doesn't show up at all in an uncoped beam end and that has caused connection failures when the cope was cut deeper than what the original connection design assumed, a coordination gap between the shop detailer and the connection designer that recurs often enough to warrant its own checklist item on many fabrication drawing reviews.
The AISC Steel Construction Manual, published by the American Institute of Steel Construction, remains the primary source for standard simple shear connection capacity tables, bolt group design, and the block shear provisions that govern coped beam end checks.