2A. Query Results At Different Nodes

 

In order to get the stresses at each node, we need to be able to identify the location of the node we want to know the stresses of.

GENERAL POSTPROC -> Query Results

      QUERY RESULTS -> Subgrid Solu

Then you will see the window that prompts you for the query you wish to obtain. In this problem, you are first asked to obtain

1. StressXX of node 2030 (at point A)

2. All stress components at node 201 (at point B) and node 640(at point C)

3. Von Mises Stress at node 2030, 201 and 640 (or point A, B and C respectively)

Here we will show how to get the StressXX at node 201 or point B.

We will have to pick node 201 which is the same location as point A. To obtain the appropriate location, keep the left mouse button pressed as you scan over the part in the ANSYS graphics window, keeping your eyes on the coordinates and node number in the "Query Nodal Results" window. When you reach the desired node release the left mouse button and a stress value will appear on the part at its respective node. If you have selected the wrong node, simply go to the "Query Nodal Results" window, and click un-pick, then click the undesired node to unselect it. Then is you want to get other components, you must repeat this process several times to query "Y-direction SY", "Z-direction SZ", as well as shear stresses "XY-shear SXY", "XZ- shear SXZ", and "YZ-shear SYZ".

Note that you can rotate the object in 3 dimensions by pressing Ctrl on your keyboard and moving the right mouse button around. Moreover, if ploting only the nodes helps you find the appropriate nodes easier, you can plot only nodes by going to the command:

Plot -> Nodes instead of Plot -> Elements

Then repeat the procedure to get the other components of stress at different nodes.

SXX at node 2030 or point A

SXX at node 640 or point C

SXX at node 195

Von Mises Stress at node 2030 or point A

In some cases, you may obtain nonzero values for stresses that you expect to equal zero, based on boundary condition constraints or other conditions. You should keep in mind that a finite element model will satisfy stress boundary conditions only in the limit as "enough" elements are used. Stress boundary conditions are not enforced strictly. What constitutes "enough" elements depends on how stressed and strains vary with position in the location you are querying. If stresses and strains change rapidly with location, a large number of elements is needed to capture nonzero and zero magnitude stressed accurately.