Empty Nodal Equivalent Stress

[AidanMcConneheyOVT]

Hi Everyone,

I am currently looking to plot the Nodal Von Mises (Equivalent) Stress for a thermal deformation analysis. However, when I do so I'm getting an error saying: "The results obtained with 'S,EQV,' are empty". Any help with this would be greatly appreciated!

Due to the sensitive nature of the actual analysis, I've replicated the issue on a simple cube comprised of two materials:

from matplotlib.colors import ListedColormap
import numpy as np
import pyvista as pv
import pandas as pd
from ansys.mapdl.core import launch_mapdl

mapdl = launch_mapdl()

mapdl.prep7()

# ~~~ Basic Material ~~~ #
mapdl.mp("CTEX",1,2e-06)	
mapdl.mp("EX",1,120000)	               
mapdl.mp("NUXY",1,0.28)

mapdl.mp("CTEX",2,4e-06)	
mapdl.mp("EX",2,60000)	               
mapdl.mp("NUXY",2,0.28)
# ~~~ Parameters ~~~ #
x = 1
y = 1
z = 1

mDivs = 4
# ~~~ Element Types ~~~ #
mapdl.et(1,"PLANE42")
mapdl.et(2,"SOLID185")

# ~~~ Geometry Creation ~~~ #
mapdl.blc4(0,0,x,y)
mapdl.lsla("S")
mapdl.lesize("ALL", ndiv = mDivs)
mapdl.amesh("ALL")

mapdl.type(2)
mapdl.extopt("ESIZE",mDivs/2,0)   
mapdl.extopt("ACLEAR",0) 
mapdl.extopt("ATTR",0,0,0)   

mapdl.mat(1)
mapdl.vext("ALL",dz = z/2)

mapdl.asel("S","LOC","Z", z/2)
mapdl.mat(2)
mapdl.vext("ALL",dz = z/2)

# ~~~ Solution ~~~ #
mapdl.slashsolu()
mapdl.allsel("ALL") 

mapdl.nsel("S","LOC","Z",0) # Set fixed corner
mapdl.nsel("R","LOC","X",0)
mapdl.nsel("R","LOC","Y",0)
mapdl.d("ALL","ALL",0)   

mapdl.asel("S","LOC","X",0) # X Area Frictionless
mapdl.da("All","SYMM")

mapdl.asel("S","LOC","Y",0) # Y Area Frictionless
mapdl.da("All","SYMM")
    
mapdl.allsel("ALL")
mapdl.antype(0) # Static
    
mapdl.tref(220) # Sets reference temperature at 220
mapdl.bf("ALL","TEMP", 20) # Sets temperature as a body force
        
sol_output = mapdl.solve()

# ~~~ Post Processing ~~~ #
mapdl.post1()
mapdl.post_processing.plot_nodal_displacement(lighting=False, show_edges=True, cmap="jet")
mapdl.post_processing.plot_nodal_eqv_stress(lighting=False, show_edges=True, cmap="jet")`

[mikerife]

Hi @AidanMcConneheyOVT
Distributed parallel MAPDL does not keep the results in memory (RAM) like shared memory parallel does. So after entering the post1 processor we have to use the SET command to read the results from the result file into the MAPDL database in memory.

sol_output = mapdl.solve()
mapdl.finish()

# ~~~ Post Processing ~~~ #
mapdl.post1()
mapdl.set('last')
mapdl.post_processing.plot_nodal_eqv_stress(lighting=False, show_edges=True, cmap="jet")

Mike

[AidanMcConneheyOVT]

Hi @mikerife,
Thank you for clearing that nuance up, that fixed it right away!