How to plot: Max. shear stress

How can I generate a plot of the maximum shear stress using plot blocks in 3DEC v5.2, similar to the way displacement contours or maximum principal stress plots are created?

Max. shear stress = Max of (|sig1 - sig2|, |sig2 - sig3|, |sig3 - sig1|) / 2


This is built in to version 7. In 5.2, you could calculate for each zone and store as an extra variable and plot that.

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Alright. Thanks for your prompt reply @jhazzard.

Hi @jhazzard and 3DEC Team,
I would like to follow up on my previous message and share the code I have written to store the maximum shear stress values in the vertex extra. Unfortunately, the calculated values do not match the expected results. I kindly request your assistance in verifying the code for any potential issues.
Many thanks,
Vijay Kiran Kota

Here is the code:

Function to extrapolate zone stresses to gridpoint extra variable
Vertex extra 1: Maximum principal stress, s1 (positive compression)
Vertex extra 2: Intermediate principal stress, s2 (positive compression)
Vertex extra 3: Minimum principal stress, s3 (positive compression)
Vertex extra 4: Maximum Shear Stress, Max. SS (positive compression)

def plot_stress                           *; first initialize to 0*
local bi = block_head
loop while bi # 0
  local gpi = b_gp(bi)
  loop while gpi # 0
    gp_extra(gpi,1) = 0.0 ; s1
    gp_extra(gpi,2) = 0.0 ; s2                                      
    gp_extra(gpi,3) = 0.0 ; s3
    gp_extra(gpi,4) = 0.0 ; MaxSS
    gpi = gp_next(gpi)
   bi = b_next(bi)

  ; Calculation of Max. shear stress
  local Max_SS = zdiff1
  if zdiff2 > Max_SS then
  Max_SS = zdiff2
  if zdiff3 > Max_SS then
  Max_SS = zdiff3

    loop local zgp (1,4)
    gpi = z_gp(zi,zgp)
    gp_extra(gpi,1) = gp_extra(gpi,1) + zs1
    gp_extra(gpi,2) = gp_extra(gpi,2) + zs2 		    	  
    gp_extra(gpi,3) = gp_extra(gpi,3) + zs3
    gp_extra(gpi,4) = gp_extra(gpi,4) + Max_SS
  zi = z_next(zi)
bi = b_next(bi) 

Hello Vijay,

i can see in your code that you did a loop through blocks and gps to set gp_extra to zero and you closed that loop after that…
Then you define some variable to store de stress differences but you never did the operation to give those variables a numeric value… also you are doing a loop throug a zone gridpoint, but you never define the zone pointer “Zi”, i suggest you to check those things.