ASDIP STEEL is a structural engineering software for design of steel members and connections. It includes the design of Flange-Plated moment connections based on the latest AISC 360 provisions.
The design of moment connections may become complex and time-consuming, since it involves the checking of multiple limit states, design provisions, and geometric constraints, for both bending and shear. Further complexity arises from the fact that all welds in flange-plated connections are field welds. This document is a step-by-step design example of a typical beam to column flange Flange-Plated moment connection, using ASDIP STEEL.
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Flange-Plated Moment Connection Example
As an example, consider the beam-to-column-flange moment connection shown below, which is part of a multistory building. Consider the loads and sizes shown below. Design the different elements of the Flange-Plated moment connection.
In the Geometry tab enter the member sizes and geometric information of the connection. In this case, the beam is W18x50 and the column is W14x68. Per the given information, a similar connection occurs at the other flange of the column. Depending on the column side limit states, it may be necessary to add continuity plates to reinforce the column.
The At-a-Glance tab shows a summary of the results organized by topic for a quick overview of your work as you go. The limit states are listed for the moment and shear connections, where you can see what limit state passes or fails to resist the applied loads. In this example the moment design ratio is 0.87 and the shear design ratio is 0.79, so the design is acceptable. The Design Checks section shows the ratios of the applicable code design provisions, as shown below.
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In the Geometry > Flange Plate tab select the flange plate width and thickness. Since the beam width is 7-1/2", let's specify a flange plate 7" wide, bolted to the beam flange. Bolt spacing 3" and edge distance 1-1/2". This geometry is adequate for 3/4" diameter bolts. Although the connection of plate and flange can be welded, in this example the bolted connection will be specified to illustrate the bolt-related limit states.
In the Geometry > Angle tab specify the size of the double angles that will resist the shear loads. In this example let's specify bolted connections to both the beam web and the column flange. Typical angle thickness is in the range 5/16" or 3/8". The number of bolts will be selected depending on the limit states controlling the shear capacity of the connection.
The Condensed tab shows the calculation results in more detail, grouped by topic and per load combination. It shows the controlling load combinations and the controlling limit states for a quick granular check. In this example the shear design strength is 124.6 k and the maximum factored shear is 98 k. The moment design strength is 213.8 k-ft and the maximum factored moment is 187 k-ft, therefore connection capacity is adequate. It should be noted that continuity plates are not required, resulting in a cheaper connection.
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In the Materials tab enter the material properties for the components of the moment connection, such as beam, column, end plate, bolts, and welds. Per the statement of the example, Fy is 50 ksi for all steel, and bolts are 3/4" A325. A36 angles will be used in this example.
The Detailed tab shows a complete set of step-by-step calculations with exposed formulas and with references to the design code, for a deep granular checking of the results, as shown below. Note the calculation of all the applicable limit states and the design checks. In this example the controlling limit state for moment is Bolt Shear Rupture, and the controlling limit state for shear is Beam Bearing Bolt Holes.
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Go to the Loads tab and enter the vertical reaction P and bending moment M at the connection per load case. The loads are given in the statement of the example. ASDIP STEEL will combine the specified loads per the ASCE 7-16 load combinations. Alternatively, user-defined load combinations can be used.
ASDIP STEEL generates images of the designed connection in plan, section, and elevation views with useful information to generate the construction drawings. In addition it shows a summary of the results for a quick check, as shown below. Note that the design can be optimized easily since any change in the input will be reflected immediately in the results.
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ASDIP STEEL includes the design of Flange-Plated moment connections, with multiple options to optimize the design in less time. The software checks the applicable limit states in shear and bending, as well as the code design provisions and geometric constraints.
Detailed information is available about this structural engineering software by visiting ASDIP STEEL. For engineering background, see the post Shear Connection: Overview of the Design Process. For our collection of blog posts about steel design please visit Structural Steel Design.
Javier Encinas, PE
ASDIP Structural Software