Welcome to the 3D Modeling video series.
This tutorial summarizes the basic sketch features available in BUILD3D, including plane, sketch, and extrude.
These tools will be used to create a 3D dam with a crack through its core.
In GeoStudio, we will start in a project with a seepage analysis associated to a 3-dimensional geometry.
Basic material properties and boundary conditions have already been created
in the Define Materials and Boundary Conditions dialogues, using the same method as in SEEP/W analyses.
Let us now launch the 3D editor by going to Define > Launch Build3D or by clicking on the Edit with BUILD3D icon in the top toolbar.
The 3D editor includes a Geometry Explorer window and a Properties window.
The Geometry Explorer contains items used to define your model, such as geometry, materials, and boundary conditions.
The Properties Window reflects the properties of selected items.
In the Geometry Explorer you will see three construction planes: Front Plane, Top Plane, and Right Plane,
which assist in drawing sketches in the 3D model space.
The Front Plane is the z=0 plane, Top Plane is the y=0 plane, and the Right Plane is the x=0 plane.
These sketch planes represent local xy coordinate systems.
It is important to note that GeoStudio assumes gravity acts in the negative y direction in both 3-dimensional and 2-dimensional analyses.
This direction is fixed so models must be constructed accordingly.
We will begin by sketching the dam cross-section on the Front Plane.
To do so, select the Front Plane and click on the Sketch Tool icon.
A 2-dimensional window will open which allows you to draw a sketch on the z=0 plane.
Select the Line icon and move your mouse cursor to the sketch plane where the grid appears.
As you move your mouse, you will see 2D coordinates of your mouse position on the plane.
As your cursor approaches a grid line the tooltip also displays ‘GSnapped’ which stands for grid-snapped,
indicating that your mouse position aligns with a grid line.
Create the dam foundation by clicking your mouse at the following coordinates:
(0,0), (0,6), (50,6), and (50,0).
Then pressing the right mouse button to close the polygon.
To create a region representing the upstream portion of the embankment dam, we will draw another polygon by clicking on:
(10,6), (23,14), and (21,6).
A third polygon will represent the dam core, with the following coordinates:
(23,14), (26,14), (28,6) and (21,6).
Finally, we will draw the downstream embankment region by selecting the coordinates:
(26,14), (38,6), and (28,6).
To edit the generated sketch, simply select the arrow icon and move the point you wish to modify.
Click the OK button in the Sketch Tools window to accept your changes.
The dam cross-section is visible on the z=0 plane, and a Profile 1 item appears in the Design History.
We can rename this geometry item ‘Dam Cross-Section’.
Let us now extrude the sketched cross-section by right-clicking on Dam Cross-Section and selecting Extrude in the dropdown list.
The extrusion dialog appears with options for direction of extrusion and number of slices.
An extrusion is always along a straight line given the user-defined direction.
The default direction is perpendicular to the sketch plane, in the z dimension.
We will leave the extrusion direction as the default.
The Slices portion of the window controls the number and spacing of solids you wish to create from your sketch.
A default of 1 appears.
This indicates that the cross section will be extruded a distance of 1 metre from the sketch plane.
We will modify this slice by right-clicking on 1, selecting Edit and entering 25.
To add a second slice at 50 m, enter 50 in the ‘Distance from Front’ edit box and click the Add button.
There are now two 25 m long slices such that the 25 m slice is offset 25 m from the sketch plane,
and the 50 m slice is offset 50 m from the sketch plane.
If we simply wanted one slice at 50 m, we can right-click on the first slice and select delete.
Click the OK button to accept your changes.
Four solids now appear under Bodies in the Geometry Explorer.
When selected, the solid is highlighted in the 3D view, and its properties are reflected in the Properties window.
If you click the expand arrow beside a solid in the tree view, you will see a solid is composed of faces.
Similarly, faces are composed of edges, and edges are composed of vertices.
Any of these geometric entitities can be assigned materials, boundary conditions, and meshing constraints as appropriate to your model.
The newly created solids do not have a material assigned.
In the Properties window you will see ‘None’ in the Material list for the selected solid.
Click the dropdown arrow next to None in the Material Associations
and select Fill for the downstream and upstream solids of the embankment dam.
Similarly, assign the Clay material to the core solid and the Foundation material to the base.
The solids adopt the colour assigned to each material.
Expanding the Materials list in the Geometry Explorer provides information on the solids belonging to specific materials.
We will now create a surface representing a crack through the centre of the dam domain.
To do so, I will first create a plane through the centre of the dam by selecting the Plane icon from the top toolbar.
In the Plane Editor, we can create arbitrary planes by selecting a face, two edges, or three vertices to define the plane.
In this case, I will select one of the faces along the side of the dam.
We can now translate this plane so it is through the centre of the dam.
To do so, click on the green chain symbol to unlock the sketch from the selected face.
We now want to move the plane 25 m in the negative z direction.
In the Direction inputs, we will change the value associated with the z direction to -1, and alter the Offset value to 25 m.
You will see that this shifts the plane to the centre of the dam.
Now that we have created the plane, we can draw the crack.
Right-click on the new plane appearing in the Design History and select Sketch.
In the Sketch Editor, we see the dam cross-section in perspective view.
For easier sketching, I will change the view to orthographic.
We will now draw a polygon representing the crack through the core.
In this case, I assume the entire core is compromised.
Thus, the polygon representing the crack follows the core region.
We now need to create a body from the crack sketch.
To do so, right-click on this sketch, go to Make Bodies, and select the Generate Surfaces option.
A new surface appears in the Geometry list representing the crack.
Note that we cannot apply a material to this surface as there are no elements associated with it.
However, we can apply a boundary condition representing the head in the reservoir.
We are now finished generating the geometry for our model.
Before solving this analysis, we would need to apply boundary conditions and generate the finite element mesh.
Please see the tutorial video Imprint Boolean Operations for a continuation of this example.
Thanks for watching and enjoy using BUILD3D.