Seismic Connections

With the help of the Seismic Detailing feature within RISA-3D, the program can handle a variety of column/beam moment and vertical brace connections with additional seismic level checks per the Seismic Design Manual (AISC 341 and AISC 358). These connections include:

• Reduced Beam Section (RBS) Moment Connection
• Welded Unreinforced Flange-Welded Web (WUF-W) Moment Connection
• Bolted Extended End Plate Moment Connections (Unstiffened and Stiffened)
• Bolted Flange Plate (BFP) Moment Connection
• Diagonal Vertical Brace Connection.
• Chevron Vertical Brace Connection.

Rules for Export

In order to export a seismic connection, you must do the following:

1. Assign the connection with a Seismic Design Rule in RISA-3D.

   This defines what level of ductility (OMF, IMF, SMF, OCBF, SCBF) will define your connection and, if it is a seismic moment connection, which predesignated type (RBS, WUF-W, BFP, BEEP, etc.) it shall be designed as.

   

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2. Assign the connection with a Seismic Moment Connection Rule, if the connection is a moment frame connection.

   

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3. Assign the connection with the appropriate Diagonal Brace Seismic or Chevron Brace Seismic connection type, if the connection is a braced frame connection.

   

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Limitations

• As with the regular moment connections, all beams in seismic moment connections must be connected to the flange of the column.
• The model must be solved in both RISAFloor and RISA-3D in order to send the lateral load combination results to RISAConnection.
• Seismic moment splice connections are not currently supported.
• The program does not put any limitations on which RISA-3D load combinations (overstrength or not) are solved and sent to RISAConnection. Therefore, we assume that the user is selecting the correct combinations to include for connection design. Once in RISAConnection, you will be able to scroll through the results from each load combination.