SkyCiv Single Angle Connection Calculator

The calculator evaluates utility ratios and design capacities for a detail that carries vertical shear out of a supported beam and into a column or girder.

All-bolted, all-welded and combination arrangements are all covered, to AISC 360 in either LRFD or ASD.

A single steel L-shape joining a beam web to a supporting column flange, column web or main girder. One of the most common shear connections in structural steel, and the simplest.

It is designed to act as a simple support: it takes the vertical shear while letting the beam end rotate a little. That flexibility is deliberate, because it keeps secondary bending moments off the supporting member and out of the frame analysis.

The economy comes from what is not there. Only one leg fastens to each member, so it goes in faster and uses less material than a double angle or a moment-resisting detail.

• Steel angle profile: a single L-shape, for example L4x3x3/8, running vertically along the beam web.
• Beam leg attachment: fixed to the web of the supported beam with structural bolts or continuous or intermittent welds.
• Support leg attachment: fixed to the supporting column or girder with bolts or welds.
• Fasteners and welds: high-strength bolts, A325 or A490, and shop or field welds sized for the eccentricity as well as the shear.

That last point is the one that catches people out. The welds and bolts here are not carrying shear alone.

Wherever the shear demand is light to moderate:

• Secondary infill floor and roof beams framing into main girders.
• Beam-to-column web connections where clearance is tight on one side.
• Platforms, walkways and industrial mezzanine framing.
• Renovation and retrofit work where only one side of the web can be reached.

The last two cases are where a single angle is not just cheaper but the only practical option. If a fitter cannot get to both sides of the web, a double angle is off the table.

Because the load path is eccentric, AISC 360 asks for more than a shear check:

• Bolt shear and bearing: shear in the fastener group, and bearing and tearout on the angle leg and the beam web.
• Angle shear yielding and rupture: gross area shear yield and net area shear fracture of the angle leg.
• Block shear rupture: tearout resistance along the bolt line, on the angle leg and on the beam web.
• Weld strength: shop or field welds on either leg, under combined shear and eccentric bending.
• Flexural yielding and rupture: bending caused by the eccentricity between the angle leg and the fastener line.

The last one is the check that separates this detail from a double angle. It exists only because the load path is offset, and it can govern.

• Select the angle section: a standard AISC L-profile, or custom leg dimensions and thickness.
• Specify the fasteners: bolt diameter, hole type (standard, slotted or oversized), pitch and edge distances, or the weld sizes.
• Define the member properties: steel grade, such as A36 or A992, and the geometry of the supported beam and the supporting member.
• Enter the factored loads: the vertical shear, to suit LRFD or ASD, plus any axial load.

Calculate, and the results come back as utility ratios with the step-by-step AISC working, so you can see which limit state is closest before settling on an angle size.

Eccentric bolt shear and block shear are the formulas most likely to be got wrong or skipped in a hand check, and on this detail they are exactly the ones that matter.

Having them run together means the eccentricity is accounted for rather than assumed away. The 3D view shows the geometry you entered, and the report carries the working, so a light connection can be sized down with some confidence rather than padded to be safe.

• Beam Splice Connection Calculator
• Bolt Calculator
• Bolted Connection Design
• Chevron Brace Connection Calculator
• Double Angle Connection Calculator
• End Plate Connection Calculator
• Flange Plate Connection Calculator
• Knee Brace Connection Calculator
• Moment Connection
• Single Plate Connection Calculator
• SkyCiv Connection Design Vs. Idea Statica
• SkyCiv Connection Design Vs. Ram Connection
• Weld Calculator
• Welded Connection Design