Document Information

Document Type: FAQ 

Product(s): STAAD.Pro 

Version(s): All

Original Author: Bentley Technical Support Group

How do I display the deflection diagram and the displacement values on that diagram?

The first step to viewing these results is to perform the analysis of the model successfully. Select Analyze from the Staad.Pro top menu bar followed by the Analysis option.

A dialog box by the name Select Analysis Engine will appear. Click on the Run Analysis button of this dialog box. After the analysis of the file is completed, click on the Done button.

The next step is to go to the Post Processing mode to view the deflection values graphically. To enter into the Post Processing mode, select Mode from the top menu bar and select Post Processing. Remember that if your analysis is not successfully completed (for reasons such as errors in your input data), you will not be able to access the Post Processing mode.

By default, the deflection diagram always opens up in the post processing screen of Staad.Pro.

From the top menu bar, choose Results - View value. Under Ranges, choose All. (The All button means the deflection diagram will be annotated for all nodes.)

Under the Node tab, you will see the options Global X, Global Y, Global Z and Resultant. Make the appropriate choice. Click on the Annotate button. Then click on the close button.

If you would like to see the diagram annotated for a different load case, select that load case from the load selection box.

After running the analysis, I go to the View menu, select Tables | Node Displacements, and select the load cases for which I want to see the values. The values are displayed in inch units. I want them in "cms" units. Changing the units using Tools | Set Current Unit doesn't seem to make a difference.

The unit system in which results are displayed on the tables is set using the facilities available under the View - Options menu. These are known as the display units. To set the display units for the node displacements, please do the following :

In the View menu, select Options - Structure units. In the category called Displacement, select the units you desire and click on OK.

I want to print out a picture which consists of a truss I have modeled with the STAAD. I want the output forces labeled right on each member. This is very similar to what would be put on to a plan sheet. Can STAAD do this or must I print out a report to get these forces?

First, you have to ask STAAD to Annotate the drawing with the axial forces. For this, please go to the post processing mode after you have analyzed the structure.

Click on the "Beam" tab on the left side and then click on the sub-tab labeled "Forces."

Click the right mouse button on the screen and select "Structure Diagrams."

From the "Loads and Results" tab, click on "Axial" under the "Beam Forces" heading.

Uncheck the "bending zz" box and click "Apply" followed by "OK."

Maximize the screen and then go to the "Results" pull down menu and select "View Value..."

Click on the "Beam Results" tab and then check the box under the "Axial" heading labeled "Ends."

Click "Annotate" and then "Close."

The axial loading values should be displayed on your screen.

When I annotate beam moments on my diagrams, I can't seem to 1) change the font by adjusting the Beam Labels option and 2) turn off the unit being written on every single number.

Annotation labels, although applied to beams, nodes, plates and solids, are not altered by the associated options (i.e View | Options | Beam Labels). In order to change the display of the annotations, go to View | Options from the main menu and choose the Annotation tab. To remove the display of the units for each annotation, simply choose the option "123.4" instead of "123.4 kN" under the Style list box in the Annotation tab. This will write the unit in the bottom right-hand corner of the screen for force, length and moment. If the units are not shown, go to View | Structure Diagrams and choose the Labels tab. Check on the option "Show Diagram Info" under the General box.

Why are my annotations for maximum bending moment or shear values not showing up in the post-processing mode?

In order to see the annotation (from Results->View Value in the post-processing mode) for a particular force or moment, the corresponding diagram must be on. For example, if one was to select maximum bending under the Beam Results tab, the bending moment diagram must be on (either MX, MY and/or MZ). Also, under the Ranges tab, make sure that the "None" option is not selected. Obviously, this would not annotate anything if it were selected. As a final note, once the annotations are visible, the size and font can be changed from the Annotation tab under View->Options in the main menu.

If I have a moment vector along the local positive Z axis does it have a twisting action going to the right along the positive direction of the axis?

If a member is drawn with its longitudinal axis (local-X) from left to right, and the local Z axis coming out of the page towards you, a positive MZ would cause tension on the top fiber, and a negative MZ would cause tension on the bottom fiber.

What are the sign conventions for moments in a 3-D structure?

The sign conventions are as follows:

Axial (FX) : Positive = Along local X axis, Negative = Opposite to local X
axis
Shear-Y (FY) : Positive = Along local Y axis, Negative = Opposite to local Y
axis
Shear-Z (FZ) : Positive = Along local Z axis, Negative = Opposite to local Z
axis

Torsion (MX) : Positive = Along local X axis, Negative = Opposite to local X
axis
Moment-Y (MY) : Positive = Along local Y axis, Negative = Opposite to local
Y axis
Moment-Z (MZ) : Positive = Along local Z axis, Negative = Opposite to local
Z axis

For axial forces,

Positive at the start node indicates compression at the start node.
Positive at the end node indicates tension at the end node.

Negative at the start node indicates tension at the start node.
Negative at the end node indicates compression at the end node.

After performing the analysis, I enter the post-processing mode to view the member end force values. I click on the Beam page on the left side of the screen and see the values listed on the tables on the right hand side. Unfortunately, the moment values are in kip-inch units, even though my current units are set to feet and pounds. What do I have to do to get the values to show up in pound-feet units in the tables?

The unit system in which results are displayed on the tables is set using the facilities available under the View - Options menu. These are known as the display units. To set the display units for the bending moments and torsional moments, please do the following :

In the View menu, select Options - Force units. In the category called Moment, select the units you desire and click on OK.

What is the purpose of the Beam - Graphs page on the left side of the screen?

This is another way to display the bending, shear and axial force diagrams on the screen.

In the post processing mode, select the Beam page from the left side of the screen. Then select graphs.

The right side portion of the screen will display the Bending diagram (MZ), shear diagram (FY) and the axial force diagram (FX) with values. In the drawing area, if you select a member by clicking on it, MZ, FY and FX of
that member will be displayed on the right hand side. To display the diagrams of another member, select that member.

How do I display the bending moment diagram and the values on that diagram, or shear forces or Axial forces?

First you must Analyze the file. Select Analyze from the Staad.Pro top menu bar. Select the Analysis option. After this, click on Run Analysis at the bottom of the small window dialog box.

After the analysis of the file is completed, click on the Done button.

Next, we go to the Post Processing mode to view the forces and results graphically.

To enter into the Post Processing mode, select Mode from the top menu bar and select Post Processing. Remember that if your analysis is not complete, you will not be able to access the Post Processing mode.

By default, the deflection diagram always opens up in the post processing screen of Staad.Pro.

To view the Bending Moment Diagrams, select the Beam page from the left side. From the top menu bar, choose Results - View value. Under Ranges, choose All. (The All button means the Bending moment diagram will be displayed for all members.)

Under the Beam Results tab, you will see the options Bending, Shear, Axial, Displacement and Stresses.
Make the appropriate choice.

Click on the Annotate button. Then click on the close button.

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

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