Tekla Structures includes a cross section sketch editor, which you can use to create your own profile cross sections. Sketched cross sections are parametric, so you can change their dimensions each time you use them in a model.
The Sketching toolbar is embedded in the Cross section sketch editor. It contains the tools you need to define and save cross sections:
This section explains how to create and edit your own cross sections, and use them in models.
It contains the following topics:
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Sketching cross sections (p. 196)•
Using constraints to lock cross section shape (p. 197)•
Defining chamfers (p. 199)•
Adding dimensions to cross sections (p. 199)•
Creating a picture of a cross section (p. 205)•
Naming, saving, and closing cross sections (p. 205)•
Testing your cross section (p. 205)•
Modifying sketched cross sections (p. 206)•
Extruding sketched polyline (p. 207)•
Using sketched cross sections in models (p. 209)•
Importing and exporting sketches (p. 209)•
Sketching tools (p. 210)Sketching cross sections
To sketch a cross section:
1. Click Modeling > Profiles > Define Cross Section in Sketch Editor.... Tekla Structures opens the:
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Cross Section Sketch Editor View and Sketching toolbar•
Variables and Sketch Browser dialog boxes2. Use the following tools on the Sketching toolbar to sketch the outline of a cross section, and holes in the cross section:
Next you need to add constraints and dimensions, and save your sketch. See:
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Using constraints to lock cross section shape (p. 197)•
Adding dimensions to cross sections (p. 199)•
Naming, saving, and closing cross sections (p. 205)Command Icon Description
Sketch polyline Sketch lines.
Sketch arc Sketch an arc.
Sketch circle Sketch a circle.
Ensure that you create a closed shape:
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Try to start sketching at a point that is easy to pick, such as a gridline intersection.•
If necessary, use the Coincident constraint tool to close it.Using constraints to lock cross section shape
After you have sketched the outline of a cross section, use the constraint tools to refine your sketch and lock the shape, for example, to straighten lines, create 90° angles, force lines to meet, and close the shape.
The Sketching toolbar includes the following tools to create constraints:
Tekla Structures will not save a cross section that does not have dimen-sions.
Command Icon Description
Sketch radial dimension Creates a radial constraint for an arc or circle.
Sketch angle dimension Creates an angle constraint for an arc or circle.
Parallel constraint Force a line to be parallel to another line.
Perpendicular constraint
Force a line to be perpendicular to another line.
Coincident constraint Force two lines to meet (extends or shortens one or both lines.) Useful when you need to close a shape.
Tekla Structures automatically creates coincident constraints:
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Where 2 lines meet•
Between line segments when you draw them with the Sketch polyline tool.•
Between the start of the first line segment and the end of the last line segment in a shape, if they are within a certain distance of each other.Fixed constraint Locks the position and angle of a line, so that other constraints do not affect it.
See the online help for a step-by-step example on using these tools.
See also Sketching cross sections (p. 196)
You can choose to create chamfers in your cross section. Then you need to add dimensions, and save your sketch. See:
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Defining chamfers (p. 199)•
Adding dimensions to cross sections (p. 199)•
Naming, saving, and closing cross sections (p. 205)Deleting constraints
To delete a constraint:
1. Click the Sketch Browser icon .
2. Select the constraint in the Sketch Browser dialog box.
3. Right-click and select Delete from the pop-up menu:
Horizontal constraint Force a line in the sketch to be parallel to the local x axis. Use with other constraints to straighten the entire profile.
Tekla Structures automatically creates horizontal constraints for horizontal lines, and lines that are almost hori-zontal.
Vertical constraint Force a line in the sketch to be parallel to the local y axis. Use with other constraints to straighten the entire profile.
Tekla Structures automatically creates vertical constraints for vertical lines, and lines that are almost vertical.
Command Icon Description
Tekla Structures will not save a cross section that does not have dimen-sions.
Defining chamfers
When you use the Create polyline tool to sketch a profile, Tekla Structures automatically creates coincident constraints between the line segments and displays a chamfer symbol where line segments meet .
To change the shape or dimensions of a chamfer:
1. For each chamfer you want to change, double-click the chamfer symbol in the sketch. Tekla Structures opens the Chamfer properties dialog box.
2. Change the shape and dimensions of the chamfer.
3. Click Modify to modify the chamfer.
4. Click OK to close the Chamfer properties dialog box.
5. Click the Save sketch icon to save the changes.
Adding dimensions to cross sections
After you have sketched a parametric cross section, use the dimension constraint tools on the Sketching tool bar to create dimensions for it.
You can use these dimensions to define the size of the profile cross section when you use it in a model.
Tekla Structures also adds the dimensions you create to the list of variables that you can use in calculations. See Using variables to define cross section properties (p. 201).
The Sketching toolbar includes the following tools to create dimensions.
Select chamfer shape Enter chamfer dimensions
Tekla Structures will not save a parametric cross section that does not have dimension constraints.
Using planes to position parts and connections
By default, Tekla Structures determines the position of parts using the outline of the part or connection, together with the options you select in the Positions section of the Position tab in the part properties dialog box. For example, the Middle option positions a part based on the geometric center of the part profile. See also Part location (p. 82).
Part positioning planes
You can have Tekla Structures use part positioning planes instead of the part profile outline to calculate the On plane and At Depth part position options.
For example, you can create part positioning planes that define the Middle option of an asymmetrical profile:
The part positioning planes appear as blue lines in the Cross section sketch editor view. Connection
positioning planes
Tekla Structures uses connection positioning planes to define the position of components relative to parts. Connection positioning planes appear as green lines in the Cross section sketch editor view.
The following image shows the default connection positioning planes and locations where you can place details when the part is a double tee slab created as sketched cross section.
Command Icon Description
Sketch free distance Creates a dimension between any two points.
Sketch horizontal distance
Creates a horizontal dimension.
Sketch vertical distance Creates a vertical dimension.
Part positioning planes
Middle option based on the intersection of part positioning planes, not part outline