Fiding Reaction Force on a Body

Generally, we have two choices to find total “Reaction force” acting on the body:

1. Defining a reference point and using kinematic coupling

The body can be coupled to a point during the model setup stage. After the analysis, the Reaction force can be checked at this node, which gives you the total reaction force.

2. Using XY Data in post-processing

Another method of finding out the Total Reaction Force without going in to the model setup stage would be to obtain the reaction forces at all the nodes on the body and then sum up the forces. In this lecture, we discuss second method, which is simpler and useful when your analysis has completed and you have already results and do not tend to submit a new job.

Using XY Data in post-processing to find Reaction Force

1. In Visualizationmodule, Click on the “Create XY Data” icon.
2. In the dialogue box which appears, toggle ODB field output:
3. Click on Continue…
4. In the XY Data from ODB Field Output Dialog box, choose
   Position: Unique Nodal
   
   
5. Then, scroll and click on the right-pointing triangle next to RF to open up.
6.  Select the component you are interested in say RF2 (Tick This)
   RF: RF2 will appear in the window below.
7. Click on the TAB: Element/Nodes
8. On the left, click on “Internal Sets”
9. On the right, the node sets automatically created by Abaqus will appear. For any part, Abaqus create a set, which has a name like “PART-1-1._PICKEDSET2”.
10. Select the part (automatically defined node-set) for the reactions you require.
11. Click on SAVE
12. In the Save XY Data dialog box, click on OK.
13. Click on “Create XY DATA” icon (the same one as before)
14. This time TOGGLE “Operate on XY DATA”:
15. Click on CONTINUE…
16. In the new dialog box on the right, will be listed various functions/operations.
    Scroll down and click on Sum((A, A….))
    This will appear in the top window.
17. On the left, all the reaction forces (RF3, say) for each of the nodes in the selected set will be listed…

Highlight all of these rows

(Method1: by holding down the left mouse button and dragging it over all the lines. Method2: easily select the first line, hold down the SHIFT key, scroll down till the last line and click on it).
19. Click on the Add to Expression button
20. Click on the Plot Expression button.
This will plot the sum of the selected component of Reactions for all the nodes in the selected node set.