Getting started -concrete frame

Model a concrete frame in GSA

This section shows you how to create a concrete section, assign it to existing members and duplicate existing members. This example will modify the portalframe from the previous tutorial into a concrete structure and will add a concrete slab.

Defining concrete sections

You can create different material properties for your Analysis and Design layers. If you have code materials for design, you can derive the analysis properties from them.

When defining sections for columns and beams, you can set which properties you will use. This section shows how to create a 600 x 600 rectangular concrete section.

1. Go to Explorer pane > Data > Properties > Section Library.

2. In the next empty row of the table, click the first cell, then the Wizard icon:

Tip: You can also bring up the wizard by double-clicking the next empty row, or pressing Ctrl+W.

3. In the Name field type '600 x 600'.

4. Change the Material to concrete.

5. Under Grade, you can either add the grade you defined earlier, or select Add code material to add another.

6. Return to the section library table. Leave the analysis field as 'from Grade'.

7. Click Profile and tick 'Rectangular'.

8. Click Next and define the profile as '600 x 600':

9. Click Next and Finish.

The profile definition STD R 600 600 will appear in the profile field, with your defined section on the right. Click OK to close the section definition wizard and return to the Section Library list.

Converting existing columns to concrete

Before you can make changes to your analysis model, you must delete any existing analysis results. This section shows how to delete the beam and change your existing column sections to the new concrete ones.

1. Delete your analysis results by clicking the Delete analyses icon:

2. In the graphic view, change to the Design layer.

Note: If the structure appears grey, check that the Deformed shape icon is switched off:

3. Click the Y elevation icon: or use keyboard shortcut Y:

4. Press E to enter Element select mode.

5. Click on the beam, then press Delete.

6. Click and drag around the columns to select them.

7. The Member Properties pane should now be visible. Select the new concrete section in the property drop down list.

Tip: You can also access the properties pane by using Right click > Modify (open properties pane).

8. In the top menu, go to: Model > Coordination tools > Synchronise members and elements or use the toobar button: to update the Analysis layer elements, and press Ok.

Duplicating concrete columns

1. Select your columns in the graphics window. Click the Copy icon to duplicate: This will open the Copy elements dialogue box.

2. Set the number of copies to '2'.

3. Set the amount to shift 8m in the Y direction.

4. Click OK to return to the graphics window. You should now see six columns. Rotate the view to inspect the columns by right-clicking and dragging.

5. Click the Section display icon: to see a 3D view of your columns.

Creating a 2D member in the design layer

This section shows you how to create a slab with a void, and mesh it using a 2D member. This allows you to create and mesh complex slabs and walls. It covers:

• Creating a grid at a specified elevation
• Defining two 2D members on the current grid
• Specifying that one of the members is a void
• Auto-meshing the slab

Note: This sections assumes that you have six concrete columns. If you are following this guide as a step-by-step tutorial, then you will need to delete any existing analysis results before proceeding.

Create the grid to draw your slab on

1. Return to the graphics window. For this example we will begin in the Design layer.

2. If necessary, click the Draw grid icon:

3. Right-click a node at the top of one of your columns and select 'Set current grid to this' from the option menu. You will be asked if you wish to create a new grid plane.

4. Click Yes to create a new grid plane at the top of the columns.

Draw a 2D member to define the perimeter of your slab

You can now define the shape of your slab by drawing on the plane.

1. Select the Add entities tool:

2. In the Properties pane, set the member type to 2D generic:

3. Click on the first corner of your slab. Continue clicking the other corners in either a clockwise or anticlockwise direction.

4. Finish by clicking back on the first corner, or pressing the Return key.

Define a void cutter member to create a hole in your slab

1. Select the Add entities tool:

2. In the Properties pane, set the member type to 2D void cutter.

3. Make a small rectangle in the centre of the larger one.

Auto-meshing the slab

1. In the top menu, go to: Model > Coordination tools > Create elements from members or click the following toolbar button:

2. The members will be meshed into multiple quad and triangle elements.

Checking the properties of your slab

1. To check your quad definition. Go to: Explorer pane > Data > Elements.

2. The property cell is highlighted in red. This shows that you do not have that 2D property defined.

Setting the properties of your slab

1. Go to Explorer pane > Data > Properties > 2D properties:

2. In the table that opens, click the first empty row and press Enter to fill the row with default values. Confirm the element type as shell, and the material as concrete. Check that the grade and analysis values are appropriate.

3. Set the thickness of your slab to '250mm'.

4. Close the 2D properties table. Confirm that the red highlighting has gone from the elements table.

Check your element data in the graphics window

1. In the graphics window, you should now be able to see that your slab is thicker.

2. Click the Section display tool to change to a line view of your model.

3. In the Properties pane, select the Labels tab. Click On elements and members, then, tick Element IDs and Property IDs:

4. The graphics view will now show the labels, and which associated property has been assigned to each element.

Note: The slab will have a property of PA1. You may need to zoom in to separate the text from the adjacent objects.

5. Return to the labels tab of the Properties pane and tick Analysis material IDs.

• Items labelled as m0 shows the analysis material is derived from the material grade.
• Tick Material grade IDs in the Properties pane, to confirm your choices.
• Concrete material grades are prefixed with a c.

6. In the labels tab, tick Element axes to confirm that the z-axis (blue line) of your slab is pointing upwards. If not go to Sculpt > Flip elements to correct it.