SimScale CAE Forum

Show overload of a structure


#1

Hi,

i’m using the drone arm sample. Changing the load from 10N -> 1000N will definitely destroy the part. The displacement will go up to 0.15m. Is there a filter/solution field that shows the overload of the part. e.g. red = structure will break.
The graphics for stress fields only show the stress relatively. e.g. red = max. stress

regards
Wolfgang


#2

Hello @wmay,
there are several possibilities, assuming that you know the yield stress of your material.

The simplest would be to just change the range for the scale in the post-processor:

Rescaled to a yield stress of 40MPa (red = broken)

You could also use a calculator filter to compute directly the factor of safety (yield stress/ von Mises stress). For values below 1 the part would “break”:

Factor of safety with yield stress 40MPa and a custom range to have a better visual feedback (blue=broken)

Best,
Richard


Euler buckling simulation
Will the program inform me of a fracture or the critical stress to which it will fail?
#3

I’ve tried setting up the filter “factor of stress” as @rszoeke described, but to no success – this field did not appear in the viewer.


#5

Hi @gkotelnytskyy,
maybe there was not enough explanation, so here is a step-by-step guide:

  1. open the solution fields in the post-processor
  2. go to +Add filter and select Calculator
  3. in the Function field put in your formula, for example 13800000/(von Mises stress) and click on Apply
  4. now you should be able to find your newly created field (by default with the name Result) in the drop-down of the filed selection
  5. you might need to hide the scale of the initial field and adapt the scale of the new one to have a good impression.

This is the original von Mises stress field from one of your projects:

And this is what I get for the factor of safety (called Result here) if I use a yield stress of 13.8MPa:


(Be aware that in this case red = bad / high stresses and blue = good / low stresses)

Best,
Richard


How can I get the exact VM value of each node?
#6

Thank you very much @rszoeke, I didn’t understand at once that variable name can contain spaces.

Is there a way to control opacity with this filter? I suspect some stressed points to be inside the joint, not visible on the surface, I’d like to hide under-critical surface.


#7

Hi @gkotelnytskyy,
you can apply a threshold filter on top of the calculator filter and set a range for the cells that should be still visible:

Make sure you uncheck the all scalars setting so that also cells where at least a single node is inside the threshold range will be shown.

Best,
Richard