How to Visual Analysis - Frames I

Given: Problem 4-29 in the Felton text shown below. Use q = 2 K/ft, L = 4 ft, E = 29,000 ksi, I = 1000 in4.

To begin building the model, open a new project.

Make it a 2D structure:

Make it a Frame:

Give it a title:

And set the defaults:

Using the same procedure as previously shown for trusses, build the following frame by adding members to the frame with the mouse. The order used to build the structure will influence where the program puts the nodes and member numbers. The structure below was built by generating member M1 starting at (0, 0) for node N1, and going to node N2 at (12, 16). Next, member M2 was generated starting at node N3 (0,16) and going to node N4 (12,16), and so on to the right.

Since the generated nodes do not have supports, edit them to turn them into supports. Click on Model, Edit, Edit nodes (or click on the Edit button, the eighth one on the bottom row) or simply double-click on the node.

Highlight Node N1

Click on "Support" and change it to "Pinned."

Notice that now there are two reactions shown at node N1.

Now let's add a vertical roller (producing a horizontal force only) at Node N3. Click on N3, then the "Support" tab, and change it to "Roller in Y." Then change N5 to "Roller in X."

The resulting structure, including the reactions, now looks:

Now lets put some pins in the members. Since members M3 and M4 are continuous, and since we really want a pin either at the END of member M3, OR at the BEGINNING of member M4, click on (and highlight) member M3. Note that if we put a pin at the end of M3, and a second pin at the beginning of M4, there would be a little piece of steel between these two pins that would be unstable, and the program would not run. Thus a single pin, releasing the strong moment capacity at the end of member M3 will be added:

Click on "Model" "Edit" and "Edit Members", or simply click on the "Edit Member" button (8th button from left on bottom row.)

Then click on the "Connections" tab. Note that by previously highlighting member M3, you have "pre-selected" the member for this operation.

Now release the strong moment Mz on the Node 2 end,

giving you the desired pin. Note how the pin is shown to the LEFT of Node N4.

Now, to change the default properties of the members to A = 10 in2, click on each member to pre-select it.

Then go to "Model", "Edit", "Edit Members"

Click on the I,A Properties tab, and change the Area of all members to 10 in2, and the Inertia, Iz to 100 in4. Note that for calculating stresses, you can enter the section modulus of the member, and for shapes non-symmetric about the strong axis, like T sections, you can enter both Sy to top fibers and Sy to bottom fibers.

Now put on some loads:

Give the Service load case a name:

Put on some NEW member loads (as opposed to node loads),

on members M3 and M4:

These loads should be Uniformly distributed, in the Global direction, directed in the Force Y direction:

The magnitude of the loads on these two members should be -2 K/ft (downwards.)

When you hit OK he sends you back to the summary sheet for this load case:

Pretty nifty. He even shows you where the loads are placed on the members:

Now lets run the problem. Click on the "Analysis Wizard" button:

 

Results:

Now to get a report on the forces in the members:

You can vary the output from your analysis by going to the "Report Wizard":

and create a new report which has the output you like:

You highlight what you want from the left column, and hit the "In" button to move it to the Reported Items columns

Several more screens will require you to hit "Next", until you get to the finish screen:

From now on your "Quick Reports" will contain the output requested.

NOTE that if you don't get the member internal forces, or something else like that it is because you did not include them in your report request. Hit "Options", "Edit Report Style", highlight the "Basic Model Report Style" and click on the "Edit Style" button, then highlight "Member Extreme Results" or whatever you are missing, and add it to the right hand window for "Reported Items."

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