How to Draw Steel Sections in Autocad
What is a User Section
A User Section is a beam section that does not fall into the usual availability of beam section sizes. This could be an extruded Aluminium section used in the construction of glass panelling for example, or a special rubber seal or custom folded stainless steel section – Anything not covered by the usual section libraries.
There are a number of reasons for needing a User Section but for this FAQ we will produce a User Section for a special stair stringer and then enable the section so that it can be used in the Stair Macro
Creating a User Section
It is no more difficult to create a User Section than it is to draw any other polygonal shape in AutoCAD. A User Section is merely a polygon shape (or shapes) with the elements assigned to specific layers.
The specific layer names are:
- Hype_CoordinateSys
- Hype_ExactInnerSection
- Hype_ExactOuterSection
- Hype_Frame
- Hype_InnerSection
- Hype_OuterSection
- Hype_RefAxis
- Hype_SectionName
- Hype_TypeName
We will return to each layer name as we progress.
As an example we will begin by drawing a section to represent a special stringer for glass walls in stairs. The shape that we draw must be a polyline and, as all things in AutoCAD, there is more than one way to achieve this.
Figure 1. In the Home ribbon, Draw tab, we can draw using the standard AutoCAD Polyline, rectangle or circle tools.
Figure 2. In the Extended Modelling ribbon, User Section tab, we can draw using the Polyline, rectangle or circle tools. These tools are the same as the AutoCAD tools above.
Figure 3.
We can also draw the shape using the AutoCAD Line tool, select all of the lines and type JOIN at the command prompt. The lines will be converted to a polygonal shape. Another option, for more experienced AutoCAD users, is to use the PEDIT command.
For this exercise we will draw the shape of the stair stringer using the Polyline tools as follows;
Open a new Advance Steel drawing, Set the view to top view and the Visual Style to 2D wireframe – as you would draw in AutoCAD 2D. Draw the shape of the new profile using the Polyline tool.
Figure 4.The finished shape. Dimensions have been added for reference but are not required in a User Section
Continue to add rectangle and text elements to your drawing until you have a drawing looking like this;
Figure 5. The elements we have added are the two single line text elements and the rectangle surrounding the shape and both of the text elements. The Rectangle must surround the drawing as shown.
So far we have drawn all of our User Section elements on the standard layer but for the User Section to work we need to assign the elements to their correct layers. If we expand the layer drop down list in the Home ribbon the layers beginning "Hype_" are not listed – we need to enable the layers from the Extended Modelling ribbon > User Section tab. The tools we need to create and activate the User section are in the User Section tab.
To begin, click on the item labelled Frame in the User Section tab to enable the special Layers for User sections.
Figure 6. Frame icon in the User Section tab.
Select the outer rectangle surrounding the User section and from the Home ribbon , Layers tab, expand the layers using the drop down arrow and set the layer for the rectangle to the Hype_Frame layer.
Set the other elements to their specific layers as follows;
- "Stair Stringer" text - Hype_TypeName layer
- "13.5 Stringer Type 1" text – Hype_SectionName layer
- Main outer profile - Hype_OuterSection layer
- Rectangular inner profile - Hype_InnerSection layer
Your drawing should now look like this;
Figure 7. User section with layers assigned
So what did we just do?
| Hype_Frame | The rectangle defines the area that contains the information for the User section. We can create multiple User sections within one drawing, i.e. all of our customer Stair Stringers can be created within the current drawing. |
| Hype_TypeName | By assigning the text "Stair Stringer" to the Hype_TypeName layer we have set "Stair Stringer" as the section type, much as PCF or RHS are section types. We will search in our material type for Stair Stringer. |
| Hype_SectionName | This is the sections available within the material type – much as 100x100x5 is a section size available in the RHS section type. |
| Hype_OuterSection | This is the profile we will see when using the Standard display type for the section. The Hype_OuterSection layer is different to the Hype_ExactOuterSection layer (see below) |
| Hype InnerSection | This is the profile we will see when using the Standard display type for the section. The Hype_InnerSection layer is different to the Hype_ExactInnerSection layer (see below) |
The exact Outer and exact Inner sections are what you see when using the display type Exact with edge display type. In our example the "stringer" is a simple shape and certainly simple enough to not bother with an exact inner and outer shape. However, the shape may contain fillets and chamfers just as the exact profile of a Universal Beam may have.
To utilise the exact outer and inner feature we need to create an exact shape for our profile and assign the outer and inner profiles to the respective exact inner and exact outer layer. Our exact shape may look something like this;
Figure 8. Exact profile with "Exact" layers assigned
The exact profile must be positioned within the Hype_Frame border and overlay the more basic shape of the user section exactly. Our final drawing should look like this;
Figure 9. Complete 'User section' drawing
When we use the "13.5 Stringer Type" 1 User section in Advance Steel we will see the Outer/Inner profile when viewed using the Standard display type and we will see the Exact Inner/Exact Outer profile when viewed using the Exact with edge feature display type. We will also be able to rotate and mirror the profile but we will be unable to position the profile using the Offset buttons.
In order to use the Offset buttons it is necessary to define the nine main points for positioning. In the drawing change the active layer to Hype_RefAxis layer. To do this, expand the layers list in the Home ribbon, Layers tab, and select the Hype_RefAxis layer. The current layer is shown in the Layers dialogue box.
Figure 10. The current layer is shown in the Layers dialogue box
At this point it may be worth saving the drawing. There is no specific path for saving your drawing, once we have written the User section to Advance Steel the drawing is no longer considered. However, other user sections can be added to the drawing so save the drawing in a logical place so it can be found easily for editing - for example C:ProgramDataAutodeskAdvance Steel 2015.1User2User_Sections
Figure 11.Reference Axis icon in the User Section tab.
Top create the nine reference axis for our User section expand the Reference Axis icon and the resulting list of icons correspond to the nine available positions. There are no rules to where you place the icons as long as they are within the Hype_frame border. The position of the section in the Advance Steel model will correspond to the icon position that you set in the User section so convention would suggest that the Top Left icon would correspond with the top left extent of the section in the drawing, the Top Right icon to the top right etc.
Some icon positions may not be so obvious – The Top Middle icon for example, there is not a line in the drawing where a midpoint can be selected for Top Middle. However, you can draw a temporary construction line and select the midpoint for the position of the icon and then delete the construction line after. Again, the Centre – Centre axis is not so obvious. You could draw a diagonal construction line to find the exact centre but would that help you to position the section? A more reasonable position for the Centre – Centre icon may be at the top – centre of the top division as this is where the glass will sit in our example – consider what you may want to align with when selecting the positions for the nine axis icons.
Figure 12. User section drawing with Reference Axis set.
The final element of our User section drawing is to add UCS coordinates. These are the positions that Advance Steel will allow us to position the UCS at Object. There is not a specific layer for this element so it is a simple matter of selecting the icon to Add Coordinates and click on the face of the object that you wish to be considered when using the UCS at Object tool in Advance Steel.
Figure 13.Add coordinates icon in the User Section tab.
Figure 14.The final User section drawing.
You may notice that when inserting both the Reference Axis icons and also the UCS Coordinate icons that they re-scale, rotate or otherwise seem to misbehave when inserting. Do not be alarmed! The functionality of the icon is not affected by such behaviour and can be ignored.
Save your drawing.
The final step in creating a User section is to generate the section, i.e. write all of the section coordinates to the User section database! Fortunately there is a tool to carry out the process.
There are two methods and both can be found in the User Section tab. – Generate selected section and Generate all sections, the choice is yours. Given that we only have one user section the time taken to generate the section will be no different whichever process we choose. However, if there were a number of user sections, and we were in the process of creating a new section to add to our library, it may be better to select just the new section and use Generate selected section – the previous sections will be ignored and not re-written to the system.
Figure 15.Generate All Sections
Select the Generate all sections icon and our user section will be written to the system as confirmed by the following message.
Figure 16. Confirmation that the section has been created
Save your drawing and close. The drawing is no longer considered by Advance Steel. However, further sections can be added to the drawing using the same process to compile a library of Stair Stringers.
Using a User Section
A user section acts in exactly the same way as one of the standard Advance Steel sections, i.e. you can cut it, drill it, notch it etc. If you have not re-started Advance Steel it will be necessary to Update defaults before the new section becomes available. If you have re-started Advance Steel the new section will be available in any case.
Figure 17. Update defaults from the Home ribbon
Our new section is listed under the Other sections selection in the sections drop down list on the Home or Objects ribbons. Select Other sections and draw your beam in the normal way. From the properties dialogue select Other profiles > All and select the Stair Stringer category from the drop down list.
Figure 18. Selecting the new User section
You will see that "13.5 Stringer Type 1" is available in the list of available sections. In fact, it is the only section available. Of course if we had created other sections in the Stair Stringer category these would also be available.
Advanced Uses for a User Section
Now we have our new stair stringer profile if may be useful to allow the profile in the Stair macro. If we create a stair using the macro and go to the Stringer profile settings we find that our new section is not available in any of the lists of material. We need to make some changes in Advance Steel to enable our new section in the stair macro. This involves making changes to one of the system databases.
The table we need to edit in Advance Steel is listed in a database table called JointGUIAllowedSections in the AstorRules database. To access the database start the Management Tools from the Home ribbon:
Figure 19. Management Tools
In Management Tools click on Table Editor followed by the small icon in the top left of the Table Editor dialogue box labelled Open ODBC
Figure 20. Open ODBC Icon
Select the down arrow adjacent to the AstorRules label and the AstorRules database will expand to show the tables contained within. Scroll down until you find the JointGUIAllowedSections table and click on the name.
We need to add a new line to the table in the right hand panel in order to allow our new stair stringer section. If you scroll down the table you will find other entries for stair stringers. Our new line will look similar to those lines. Scroll to the very bottom of the table to expose the blank line. We will add our new data to this line.
The first entry field is labelled Key - This must be a unique number. We could just use the next number in the sequence. However, in future releases of Advance Steel Autodesk may add lines to the table also! You can see that using the next available number may prove problematic in that instance. Choose a number well away from the last number in the list, for this exercise we will use 10000.
The second field is JointName – Comparing the other stair entries this field is Stair. This is the name of the joint that controls the stair macro so we will enter Stair in our new entry.
The third field is JointControl – Again comparing the other stair entries this field is Stringer. It follows that we will use the same name for our new entry.
The forth field is AllowedSectionType – For this field we deviate slightly from the other stair entries. A "section type" may be PFC, or Flat or any other standard section. These have a special code to denote the shape. Our profile is a non-standard shape so none of the special codes will suit our application. If we click on the name Section Shape we are presented with a drop down icon and another selection Section Class – Our user section is a Section Class so select that option.
The last field is AllowedSection – In this field we have to give the name of our new section type – Stair Stringer in our case. However, we have to append the name with the letters Usr so the entry for this field will be Usr Stair Stringer(Stair Stringer should be written exactly as it was in the Hype_TypeName of our user section.
The last line in your table should look like this;
Figure 21. New line created in the JointsGUIAllowedSections Table
We can now close the Management Tools. There is no need to save the table or the database as the new information is saved automatically on exit. We do, however need to Update Defaults in Advance Steel before the new model role becomes available.
The Update Defaults button is on the Home ribbon under the Settings tab – where we found the Management Tools icon earlier.
Figure 22. Update Defaults
If we return to our stair model and open the stair Joint properties the new user section is available from the stringer material option.
Figure 23. Stair Stringer is available in the stair macro
Figure 24.Stair showing result of using the new User Section for stringer and landing profiles.
Source: https://graitec.com/faq-item/faq-2478-how-is-a-user-section-in-advance-steel-cr/
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