Trim Connected Section Ends to Correct Geometry

When a section is connected to a section that already exists, the end points of the new section are usually positioned automatically by reference to the currently defined Pline Rule. If this rule has not been set up properly, the geometry at the point of connection may be inappropriate. For example, in plan view, the connection between a column and a beam a pictoral representation of:

rather than the intended configuration:

To correct this, the length of the beam section is trimmed to an explicitly picked pline of the owning section. These errors must be corrected before the model is developed further otherwise problems may arise when bracing is connected.

1. Zoom in to the graphical view and change the direction of view to show the detailed geometry of each connection point in turn.

   Look for any examples where an attached section has been trimmed to the wrong length.

2. You can pick the end of a GENSEC to be trimmed, the appropriate end of the GENSEC will be marked and automatically trimmed to the:

   • Appropriate PLine or you can force the PLine

   • Picked Section

3. From the main tool bar you can click Edit > Undo if required.

If any are found correct them:

4. From the main menu bar select Connect > Trim to Pline > Pick (force).

   You are prompted to ‘Identify section end to be trimmed’.

5. In the 3D view, pick one of the ends to be corrected (as shown shaded in the diagram).

   You are prompted to ‘Identify pline to be trimmed to’.

6. Change the view if necessary and pick the pline which corresponds to the required section end point (typically NAR/NAL for a web connection or TOS/BOS for a flange connection, as shown by the black dots in the diagram (for further information, refer also to Structural Catalog Guide).

   The pointer shape changes when it is positioned on a pline and the status bar identifies which pline is selected at any given moment.

7. Press ESC to action the change.

   Note: Use the graphical manipulation facilities to zoom in close to the joint of interest. Also, it is advisable to switch to wireline display mode (press F8, this toggles between wireline and shaded display modes).

8. Repeat this sequence, alternately picking section ends and plines, until all errors have been corrected.

9. If you are confident that the correct selections have been made, pick any number of section/pline pairs before you press ESC..

To check the current pline rule (if any), from the main menu bar:

10. Select Settings > Pick Filters > Plines.

11. A Pline Filter window is displayed populated all currently defined rules; this probably shows No Rule and Normal, with the former selected.

    

    The Normal rule handles the connections that the rule to be created below is going to handle.

12. Click Define Rule to display the Define Rules window.

13. Enter the Name as Extremities (this is used to identify the rule in subsequent lists) and the Description as Flange or web face for trimming at connection.

14. Enter the Rule below (take care to include the apostrophes and commas exactly as shown):

    PKEY inset (’TOS’,’BOS’,’NAL’,’NAR’,’FOC’,’BOC’,’TOC’)

15. Click Include to add the new rule into the list.

    The result is displayed in the Defined pane of the Define Rules window:

    

16. Click OK.

17. Select the Extremities rule on the Pline Filters tab of the Snap Settings window to make this the current rule.

18. Click OK and close the Picking Control window.

Note: A full explanation of the ways in which pline rules are set and applied is beyond the scope of this manual. Suffice it to say that the rule set here may be interpreted as ‘Select a pline which has any of the PKEY settings specified in the list’. (Refer to Structural Catalog Guide for diagrams showing how these plines are positioned for typical steelwork profiles.)