In this
tutorial, we will analyze an over head water tank using STAAD.Pro V8i. The
detailed procedure is given below.
1. Open STAAD.Pro
V8i and create a new Space structure
with Meter and KiloNewton as Length Units and Force Units.
2. Select the
Beam page under Geometry tab; the Snap Node/Beam window is displayed.
3. Close the Snap Node/Beam window.
In the Nodes window, create the nodes with the
data given below. Figure-1 shows the nodes created.
Node
|
X
m
|
Y
m
|
Z
m
|
1
|
0
|
20
|
0
|
2
|
1
|
20
|
0
|
3
|
1
|
23
|
0
|
4
|
4
|
25
|
0
|
5
|
2
|
17
|
0
|
6
|
4
|
18
|
0
|
Figure-1
The Nodes created
Now, we
will create the members in the upward direction so that the plates could be
created with the same orientation. If the plates are created in different
orientation, you cannot assign a single load case to plates with different
orientations.
4. Create the
members with the data given below. Figure-2 shows the members created.
Beam
|
Node
A
|
Node
B
|
1
|
5
|
2
|
2
|
2
|
1
|
3
|
2
|
3
|
4
|
3
|
4
|
5
|
5
|
6
|
 |
| Figure-2 The Members created |
Now, we will
create a segment of the tank using the Circular
Repeat tool.
5. Select all
the members and then choose the Circular
Repeat tool from the Geometry menu; the 3D Circular dialog box is displayed.
Enter the
values as shown in Figure-3.
 |
Figure-3
The 3D Circular dialog box
|
6. Choose the
OK button; the model will be
repeated at 20 degrees with rotational axis as Y-axis.
7. Select all
the members and then select the Create Infill Plates option from the Geometry
menu; the plates will be automatically created in the areas enclosed by the
members.
8. Select the
outer periphery beams as shown in Figure-4 and delete them.
 |
Figure-4
Periphery beams to be deleted
|
Now, we
will apply loads to the plates.
9. Select the
Loads & Definition page
from the General tab; the Load & Definition window is
displayed.
10. Select the
Load Cases Details node in the Load & Definition window and choose
the Add button; the Add New: Load Cases dialog box is
displayed with the Primary node
selected by default.
11. Select the
Fluids option from the Loading Type drop-down list and enter Fluid
Loads in the Title text box.
12. Choose the
Add button; the primary load case
will be created under the Load Case
Details node of the Load &
Definition window. Close the Add
New: Load Cases dialog box.
13. Select the
newly created Fluid Loads load case and choose the Add button from the Load & Definition window; the Add New: Load Items dialog box is displayed.
14. Select the
Plate Loads node in the Add New: Load Items dialog box; the Pressure on Full Plate page is displayed
by default.
15. Enter -76 as load intensity in the W1 text box and select GY as the load direction. Choose the Add button; the load is added under the
Fluid Loads load case.
16. Select the
Hydrostatic page from the Plate Loads node in the Add New: Load Items dialog box; the Hydrostatic page is displayed.
The
options are unavailable as no plates are selected.
17. Choose the
Select Plate(s) button from the Add New: Load Items dialog box; the Selected Items dialog box is displayed.
18. Choose the
Plates cursor and select the plate
as shown in Figure-5; the plate number is displayed in the Selected Items(s)
dialog box.
 |
| Figure-5 The selected plate
onto which load is applied |
19. Choose the
Done button from the Selected Items(s) dialog
box; the Selected Items(s) dialog box is closed and the
options are available in the Hydrostatic
page.
20. Enter -53.9 in the W1 edit box and -0.009
in the W2 edit box.
21. Select the
Y and Local Z radio buttons in
the Interpolate along Global Axis and Direction of pressure areas, respectively.
22. Choose the
Add button; the load is added under
the Fluid Loads load case.
23. Similarly,
add the hydrostatic load of the magnitude ranging from -53.9 to -66.4 kN/m2 on
the plate just below the vertical plate, as shown in Figure-6.
 |
Figure-6
The selected plate onto which load is applied
|
Now we
will assign the uniform pressure created in previous steps onto the bottom
plate of tank.
24. Select the
uniform pressure load and assign it to the plate as shown in Figure-7.
 |
Figure-7
The load applied onto the bottom most plate
|
25. Create a
new load case for dead loads and add self weight and a uniform load for
railing. The railing will be placed onto the beam situated at the edge of the
cantilever plate, as shown in Figure-8.
 |
Figure-8
The self weight and railing load applied
|
Now we
will provide sectional properties to the model.
26. Select the
Properties page from the General tab; the Properties – Whole Structure
window is displayed.
27. Choose the
Thickness button from the Properties – Whole Structure window; the Plate
Element/Surface Property dialog box is displayed.
28. Enter 0.15 as thickness in the Node 1 edit box and make sure that the Concrete option is selected from the Material drop-down list. Choose the Add button; the Plate Element/Surface Property dialog box is closed.
29. Select the
Assign to View radio button from the
Properties – Whole Structure window and then choose the Assign button; the property is assigned to each plate created.
30. Choose the
Define button from the Properties – Whole Structure window; the Property
dialog box is displayed.
31. Select the
Rectangle node; the Rectangle page is displayed. Enter 0.45 and 0.30 in the YD and ZD edit boxes respectively.
32. Choose the
Add button; the Property dialog box is closed and the property is added to the Properties – Whole Structure window.
Assign the
newly created property to the members in the model.
33. Similarly,
assign a cross sectional property of 0.15m x 0.15m to the member carrying
railing load.
Figure-9
Properties added and assigned to the model
34. Select the
Support page from the General tab; the Supports – Whole Structure window is displayed.
35. Choose the
Create button; the Create Support dialog box is displayed
with the Fixed tab chosen by
default.
36. Choose the
Add button; the fixed support is
added to the Supports – Whole Structure
window.
37. Assign the
fixed support created to the lowermost nodes, as shown in Figure-10.
 |
Figure-10
Fixed supports added to the model
|
38. Select the
plates and members using the Geometry
Cursor and choose the Circular Repeat option from the Geometry
menu; the 3D Circular dialog box is
displayed.
39. Enter the
values as shown in Figure-11.
Figure-11
The 3D Circular dialog box
40. Choose the
OK button; the model will be
repeated at 360 degrees with rotational axis as Y-axis
Figure-12
shows the water tank created.
 |
Figure-12
Model of water tank created
|
Figure-13
and Figure-14 shows the 3D rendered views of the water tank.
 |
Figure-13
3D rendered view of the water tank model
|
 |
Figure-13
3D rendered view of the water tank model
|
Now, we
will analyze the model created.
41. Select the
Perform Analysis option from the Analysis
fly-out in the Commands menu; the Perform Analysis dialog box is displayed.
42. Close the Perform Analysis dialog box and select the Run Analysis option from the Analyze
menu; the STAAD Analysis and Design
window is displayed showing the progress of solution.
43. Once the
analysis is complete; select the Go to
Post Processing Mode radio button and choose the Done button; the Results
Setup dialog box is displayed.
44. Choose the
Apply and the OK button; the post-processing mode is displayed along with various
results.
45. Choose the
Plate tab; the Diagrams dialog box is displayed.
46. In the Diagrams dialog box, select the MY (local) option from the Stress type drop-down list and choose
the OK button; the stress contours
is visible in the model along with the legend.
Figure-15 shows the
MY (local) stress contours in the model.
 |
| Figure-15 MY (local) stress
contours of the model |
Similarly,
you can view various other stress contours for the plate elements.
