Creating a Bar Joist Pattern

You can create in your building project a bar joist pattern, also known as an open web steel joist. Used for direct floor-deck or roof support, a bar joist consists of top and bottom chords, a triangulated web system, and bearing seats.

See Also
Creating a Building Structural Grid
Creating a Reference Plane Grid
  1. Create a building grid if the project does not already have one.

    Use a structural grid that you create in either Buildings and Civil Structures Design or Buildings Space Planning with either the Building Grid or Reference Plane Grid .

  2. From the Steel section of the action bar, click Bar Joist Pattern .
  3. To select the series and designation, perform the following steps:
    1. From Series, select the catalog series for the bar joist.
    2. From Designation, select the size of the joist.
  4. To set the joist pattern location, from the Bar Joist Pattern dialog box, from Create Mode, click either:
    OptionDescription
    Single

    		 Inserts a bar joist relative to only the selected segments.
    Along gridline

    		 Inserts bar joists relative to all similar segments along the gridline of the selected segments.
    All in the story

    		 Inserts bar joists relative to all similar segments in the same story as the selected segments.
    Above and below

    		 Inserts bar joists relative to all similar segments above and below the selected segments.
    All in the building

    		 Inserts bar joists relative to all segments in the structural grid.
  5. From Spacing, choose either:
    OptionDescription
    Count Sets the number of joists to place and has the system automatically determine the spacing.

    To complete the selection, enter in Count the number of equally spaced joists.

    • To add a member at one end, select the Add member at 1 end checkbox.
    • To add a member at another end, select the Add beam at end 2 check box.
    Spacing Sets the spacing between the joists and has the system determine the number of joists to place.

    To complete the action:

    • In the 3D area in the value box, enter the spacing.
    • To create a pattern with the end spacing less than half the entered spacing distance, select the Smaller end spacing check box.
    • To add a member at one end, select the Add member at 1 end checkbox.
    • To add a member at another end, select the Add beam at end 2 check box.
  6. To determine the orientation, from Orientation, click one of the following:
    OptionDescription
    Perpendicular Places joists perpendicular to the first selected grid segment.
    Parallel to end 1 Places joists parallel to a line between the start of the first selected grid segment and the start of the second grid segment.
    Parallel to end 2 Places joists parallel to a line between the end of the first selected grid segment and the end of the second grid segment.
    End 1 & 2 Places joists by interpolation between the direction of the two ends.
    The system displays a preview of your selection.
  7. To create a bar joist pattern in a new geometrical set, select the Create in a new geometrical set check box.
  8. Expand Options and specify the following values:
    1. To set the offset in the horizontal direction, enter or select the U offset.
    2. To set the offset in the vertical direction, enter or select the V offset.
    3. From Rotation, enter or click the joist rotation angle.
  9. To enter custom values for the joist features, expand End 1 and End 2:

    Note: To specify symmetrical joist ends, enter the same values for End 1 dimensions and End 2 dimensions. For asymmetrical joist ends, enter separate values for each end.

    1. Enter or select the length of the Top extension.

      The top chord extension supports overhangs by extending the top chord.

    2. Enter or select the length of the Bottom extension.

      The bottom chord extension supports elements such as a suspended ceiling or piping. It can also provide additional stability for the joist by extending to a vertical support.

    3. Enter or select the Seat depth.

      Seat depth is the measurement from the top of the top chord to the bottom of the bearing seat. Each series has a standard seat depth, which is the default value. Since you can order joists with custom seat depth, you can enter a custom seat depth value.

    4. Enter or select the Seat location.

      The bearing seat location is the dimension from the end of the bearing seat to the grid segment. The dimension can be a positive or negative value.

  10. Expand Grid Segment Display and in the Grids to Display box, select the grids to display, and then select the checkboxes according to the requirement:

    Option Description
    Show grid segments Displays grid segments between grid points.
    Show curved grid segments Generates curved grid segments from curved grid lines.
    Show perimeter segments Displays grid segments and points on the perimeter of the structural grid.
    Show interior segments Displays grid segments and points in the interior of the structural grid.
    Note: To hide the specific element, clear the check box.

  11. Click .

The tree lists each Bar Joist Pattern under Joist Patterns. To see Joist Patterns, expand the Structure node.

Note: To dissolve the bar joist pattern into individual bar joists, from the context toolbar click Dissolve Pattern Feature.