How to display displacement?

[zhang-rite]

Hi

Here is a native question. My problem has primary variables "disp_r disp_z". In default output exodus file, there shows a variable of "disp_". Now I want to see the differential displacement of each step to a special time (_initial).
The questions are

• How to make "disp_r" and "disp_z" can be visualized separately by exodus file?
• how can I define "disp_r_initial" in auxkernel or in kernel or in some other ways then I can calculate the difference?

I know the way for strain and stress. I just don't know how to do this for primary variables. Thank you.

[WilkAndy]

Seems like i'm your personal assistant! :-)

1. This is a paraview question. Look up the top of the paraview window. You should see a box containing a list of variables you can display. One of them will be "disp_" as you have noticed already. Click it. Then look to the right of this box, and you should see a box with "Magnitude; x; y; z" in it. Choose your desired component (your disp_r will be called "x" by paraview)

2. Use ParsedAux and execute on initial. Eg

 [disp_r_initial]
    type = ParsedAux
    args = disp_r
    function = disp_r
    variable = disp_r_initial
    execute_on = initial
  []

You can also define

 [disp_r_change]
    type = ParsedAux
    args = 'disp_r disp_r_initial'
    function = 'disp_r - disp_r_initial'
    variable = disp_r_change
 []

[zhang-rite]

Wow, Andy, thanks again and again 😄 !