Connections

The Connection Rules spreadsheets and settings are used for two purposes in RISAFloor:

  1. The analysis and design of columns with respect to the eccentricity effects caused by connections.
  2. The integration with RISAConnection for the design of hot-rolled steel connections.

Note:

RISAConnection can be used with RISAFloor and/or RISA-3D to design hot-rolled steel connections. The integration will send the member geometry, loads, and connection type information into RISAConnection. You can then open RISAConnection to edit/adjust the details of the connection. When satisfied with an appropriate connection design, you can then send the connection design results back into RISAFloor and RISA-3D for results presentation.

Available Connection Types

The list of available connection types depends on what version of RISAConnection you are integrating with. The list below represents the available connection options from the current version of RISAConnection:

See Troubleshooting below for more assistance with connection type limitations.

Integrated Connection Design Procedure

The steps required to design connections using this integration are as follows:

1. Completing the Full Structural Model

You must first draw your model in RISA-3D or RISAFloor. It is important that you use the Member Type (Column, Beam, VBrace, HBrace) designation properly. Otherwise your connections will not be designed. Keep in mind that connection design will only work for hot rolled connections at this point. Future versions will add to the current RISAConnection connection type capabilities.

2. Defining Connection Rules

Next, you must define Connection Rules. These rules allow you to define which types of connections you want to design in your model. You must have a rule for each type of connection you want considered. You may also want to create two separate rules for the same connection Type so you can manipulate these groups separately.

To open the Connection Rules spreadsheet click the button on the Data Entry toolbar. Then create rules for each type of connection that you want to be designed with RISAConnection. The spreadsheet entries are explained below:

3. Assigning Connection Rules

Once the Connection Rules are defined they must be applied to the member ends in your model.

Assigning the Connection Rules Graphically:

Assigning the Connection Rules in the Beams Spreadsheet:

The Connections tab of the Beams spreadsheet provides a place to assign, edit and view Connection Rules and column eccentricity settings as they apply to individual members.

Note:

4. Assigning Load Combinations

Once you have all of your Connection Rules assigned properly you must define which load combinations that you wish to use for connection design.

On the Design tab of the Load Combinations spreadsheet there is a check box for Connection. This check box defines whether you want your connections designed for that LC or not.

There are times where the member design may be designed by LRFD methods and the connections designed by ASD methods. This check box allows for that flexibility.

5. Designing Connections

To design connections you must first have either a Single LC or Batch solution present. Once there is a solution, there are two ways to design connections.

  1. Choose Solve - Design Connections.

This option will not automatically open RISAConnection. Instead, it will run in the background, using whatever default or previous settings are in RISAConnection. Once you've done this the Connection Results browser will be populated. To fully export into RISAConnection, use the Director tool, as shown next.

  1. Choose Director - RISAConnection.

This option will automatically launch RISAConnection where you can modify the connection parameters, such as number of bolts, clip angle size, clearances, etc., for all the valid connections in your project (see the RISAConnection Help file for more information on how to design connections using RISAConnection). You can then solve your model in RISAConnection and then send the information back to RISAFloor to populate the Connection Results browser.

RISAConnection File Creation and Workflow

When using RISAConnection integration, a RISAConnection file will be created automatically. The file will have the same naming convention as the RISAFloor file and will be created in the same directory as the RISAFloor file. It will have a .rcn file extension.

Once this RISAConnection file is created then you can use this file separately to make connection changes. The file can be transferred to another machine and worked on separately. Items related to the connections can be modified (bolt criteria, weld criteria, connector sizes, clearances, edge distances, etc.). You can then modify/design your connections so that they now work. Then, simply move that file back to the location where the RISAFloor model is located and then redesign connections in RISAFloor. These changes will then be considered.

Note that any items defined by the RISAFloor models can not be modified (beam/column sizes, bolted vs welded connections, design code, etc). Any of these changes must be taken care of in RISAFloor and then sent back over to RISAConnection.

6. Connection Design Results

Once the connections have been designed in RISAConnection from either of the methods above the results will be available in RISAFloor. You can view the results browser or see color-coded results graphically.

Connection Results Browser

When viewing this browser there is a button at the top of the screen, Detail Results for Current Connection.

Clicking this button will open up RISAConnection to this specific connection, allowing you to take a further look at the connection results and allow you to edit connection properties in a quick, efficient manner.

Note

Viewing Results Graphically

Click on the Member End Display button from the Windows toolbar to view the connection results directly on your model, in color-coded view. The labeling will display the governing unity check value.

If you are in a graphic view and have valid connection results you can also press the Connection button on the left-hand side of the screen.

This will give a Connection cursor and allow you to click on a member end that has a Connection Rule defined and will open RISAConnection to the specific connection that you clicked on.

7. Multiple Round Trips Between RISAFloor/RISA-3D and RISAConnection

When round tripping between RISAConnection and RISAFloor/RISA-3D multiple times there are a few items to consider:

Troubleshooting RISAConnection Integration

If you have difficulty getting your RISA-3D or RISAFloor model to integrate into RISAConnection, it is possible that you have defined connection or member information incorrectly, or there may be a program limitation which prevents the integration. Please see below for assumptions, modeling rules, and possible error messages.

Moment Connection Considerations

The following moment connections are currently supported in RISAConnection:

Shear Connection Considerations

The following shear connections are currently supported in RISAConnection:

Vertical Brace Connections

The following vertical brace connections are currently supported in RISAConnection:

Diagonal Brace Connections

In order to properly export a diagonal brace connection to RISAConnection you must obey the following rules:

Chevron Brace connections

In order to properly export a Chevron Brace connection to RISAConnection you must obey the rules below:

Knee Brace Connections

In order to properly export a Knee (or Kicker) brace connection to RISAConnection you must obey the following rules:

Splice Connections

RISAConnection can design wide flange splice connections for beam and column splices. These can be either shear or moment splices. Keep in mind these items when creating your model:

Base Plate Connections

RISAConnection can design single column base plate connections for shear and/or moment forces. Keep in mind these items when creating your model:

Brace to Base Plate Connections

RISAConnection can design vertical brace into a column base plate connections for shear and/or moment forces. Keep in mind these items when creating your model:

Truss HSS T-Connections

RISAConnection can design HSS T-Connections that have been exported from your RISA-3D model. Keep in mind these items when assigning the connection rule in RISA-3D:

Integration Error Messages

If you try to send a connection to RISAConnection from RISAFloor or RISA-3D, the program will test whether that is a valid connection. If the program finds the connection or the Connection Rules to be incorrect or unsupported, then the program will not design the connection and will give the error in the Connection Results spreadsheet - Limit State column.

The possible error messages are:

Connection Types Not Currently Supported

RISAFloor and RISA-3D Connection Design Interaction

RISAFloor and RISA-3D both have the ability to have their connections designed with RISAConnection. Thus, there are three possible scenarios for connections between RISAFloor, RISA-3D and RISAConnection:

  1. Connections that are only in RISAFloor (Gravity connections in a combined RISAFloor/RISA-3D model).
  2. Connections that are in both RISAFloor and RISA-3D (Lateral connections in a combined RISAFloor/RISA-3D model).
  3. Connections that are only in RISA-3D.

The third option above does not involve RISAFloor, thus it will not be discussed here.

RISAFloor Gravity Member Connections (Scenario 1)

Connections that are gravity in RISAFloor (option 1) are only RISAFloor members, which makes this more straightforward. When designing connections from RISAFloor you get a very similar behavior to what is shown in the behavior above.

The difference is when you use the Director to go into RISA-3D and then into RISAConnection, the Gravity connections are still in the RISAConnection project. The .rcn file contains BOTH RISAFloor AND RISA-3D connections. Therefore, when entering RISAConnection from RISA-3D, you will see more connections in RISAConnection then just those sent over from RISA-3D.

RISAFloor Lateral Member Connections (Scenario 2)

Additional items to consider are:

Load Combinations

Lateral connections in RISAFloor will also come into RISA-3D. Thus, two sets of load combinations will come into RISAConnection. Below is the Load Combination drop-down list from RISAConnection after coming in from a RISAFloor/RISA-3D model.

Here we can see that the RISA-3D LC's come in first followed by those from RISAFloor.

Note:

When reporting results in the Connection Results spreadsheets, both programs may list load combinations from the other program if those LC's happened to be governing.  In RISAFloor it would look similar to the image below:

Naming Convention

RISAFloor and RISA-3D have different naming conventions for members. Thus, members taken from RISAFloor to RISA-3D will NOT have the same name between both programs.

RISAConnection will ALWAYS use the RISAFloor naming convention. This may be a little confusing. One way we have made this easier to comprehend is that in the Connection Results spreadsheet in RISA-3D we give BOTH the RISAFloor and RISA-3D label.

In this image the F1_B labels are the RISA-3D labels. The labels in parentheses are the RISAFloor labels.