and Using Algor with Trusses and Beams Chad McIntosh Keith Brooks Ashley McKnight Chris Batsch

Topics 1.Intro to Algor 2.Things to know for beam and truss problems 3.Step-by-Step beam example

Finite Element Analysis Used to eliminate excess material. Determine high stress points. Illustrated weak and strong points of model. Show displacement of each element

Algor Software Easily import from CAD program Negatives- Time consuming Must be an assembly to be imported Needs high-end computer

What you need for trusses and beams Geometry or nodal locations Material Cross-sectional area Boundary conditions Rotation Translation Loads (location and magnitude)

Superdraw Algor’s drawing program Has standard drawing tools Easily used for simple structures

Example Use algor to show the displacement of a 1000lb force on the figure to the Right. Material 1 is Aluminum (6061-T6) and Material 2 is Steel (4130)

Open Superdraw III Instructions

Click Add Menu► Line Then enter 0 in X=0 Y=0 in the lower right (Circled In Red), then hit enter Repeat this step entering (4,0), (8,0) and then hit Escape Instructions

Go to View► Enclose and you should have the Picture above. Now we will begin to supply Algor with all the necessary information. Instructions

Since our example has two materials we must make different groups for them in Algor To create a group first click the Model Data button on the center of the bottom tool bar (Highlighted In Red). The Model Control Box should appear. Instructions

Click Add on the Group Options of Model Data Control Box Next Click the Red box with a 2 in the center, This will add a second group Instructions

Now go to Select► Box and then enclose piece 2 in a box To make piece 2 a part of group 2 go to Modify►Update Object Parameters►Group Number and then select Group 2 and now piece 2 should be red Instructions

Now we must apply the boundary conditions. First we address the beam to wall area. Start by going to FEA Add►Stress and Vibration Analysis►Boundary Conditions Instructions

Next click on the Change Values button on the Boundary Conditions box and you will see the menu above The Tx stands for Translation in the X direction and Rx Rotation in the X. Since there our beam is attached to wall all movement is restricted so leave all boxes checked in and click Done Instructions

Now Right click the far right point at the origin and you will see sign this means that the point is constrained from all movement Click Done and we will add the force to the right of the beam Instructions

Go to FEA Add►Stress and Vibration Analysis►Nodal Forces and you will see the menu in Figure 1 We must first set up the direction of the force so click vector and click the X Direction (In Figure 2) button and then Done Now click Magnitude button (In Figure 1) and enter 1000 Right click the right end of the beam and your force will show up Now our boundary conditions are finished Your beam should now look like Figure 3 Figure 1 Instructions Figure 2 Figure 3

Now we must identify the material properties of our beam. Click on the button below to bring up the Model Data Menu menu (Figure 4). Click on the box for Group 1 under element and change it to beam and then click done and repeat this for Group 2. You will see beam under element Click the Data box of Group 1 and you will now be asked to save. You will now have a menu in which you can define your units (Figure 5). For the Example we want English (in) so then click OK. This will now open a program that is specific to beams called beam design editor. Instructions Figure 4 Figure 5

In this program we will set parameters specific to each beam. Click Add/Mod ►Sectional►Value when you do this a cursor will appear at the bottom. Now use to go to I 2 (moment of inertia) hit to clear the current value and enter 2e-4. Do this for I 3 and hit enter then twice to get back to the main menu. Now click donE and you will be asked to save. Save your work and you will go back to the Model Data Control box. Instructions

Repeat this Beam program steps for beam 2 and use the same value for your moment of inertia Now click material under the Model Data Control box for Group 1. The Element Material Selection (Figure 6) box now appear select Aluminum (6061-T6) and click OK Make Group 2’s material Steel (4103) Instructions Figure 6 Now click Global on the Model Data Control box and the Linear Static Stress Analysis Box (Figure 7) will appear. Change the Pressure to 1 under the multiplier tab. Under the Output tab check in the Element Data, Nodal Data, Displacement/eigenvector Data, and Stress Data. This chooses what information Algor will give us back. Click OK Figure 7

Now click Analyze on the Model Data Control box and the box in Figure 8 will appear which shows how much memory this analysis will take. Click Analyze and Algor will go to work!!!! Once Algor has finished analyzing click Done To view the Results click the Results on the Model Control box Click Ok when Figure 9 appears and Superview will open To view what the stress related to the color of the beam relates to got to Results►Beam and Truss Stress and Figure 10 will appear. Click Done. Instructions Figure 8 Figure 9Figure 10

Instructions We can also show the deflection of our example to do this go to Results►Displacement Data►Displacement Model and the box like Figure 11 will appear. Check in Displaced Model On and Undisplaced Model On boxes and then Done. Your final picture should look like Figure 12. Circled in red you can see the slight displacement that will occur. Figure 11 Figure 12

Questions

References “A First Course in the Finite Element Method Using Algor”, Daryl L. Logan