Corrugated profile simulation

I need to simulate a corrugated profile in HDPE (High Density Polyethylene)
I have doubts about the correct procedure.

Basically that’s what the uploaded image suggests.

And what are your doubts ? Do you have an English version ? If not, please translate the parts that are important for your question.

Oh no, the image is just to illustrate the simulation, forget the text.

My question is about which simulation mode to use.
I’ve seen several ppm tutorials, but none gave me a clear path.

  1. Use symmetry (here a quarter of the model could be analyzed).
  2. If the profile is thin-walled, mesh it with shell elements.
  3. Nonlinear static analysis (with Nlgeom) will be the one to use here. Unless the dynamic effects have to be included.
  4. If possible, apply displacement instead of force - it’s much better for convergence. You can always measure the reaction force to know if you reached the desired level of loading.
  5. Define contact between the profile and the plates.
  6. Apply rigid vody constraint to plates if you can treat them as rigid for simplification (which is usually the case in such situations).

And don’t forget buckling if you are under compression. :slightly_smiling_face:

This may categories as standard compression test of part/member strength and stability. Someone need to activated geometric nonlinearity, imperfection and plasticity. This example and discussion can be found on CalculiX forum i’ve been replied about nonlinear buckling.

Guys, thanks for the tips.
I will test the suggestions.
sds

Hello @deciodalmolim, seeing other Brazilians in this community is always nice.

Since the ABNT normative says the goal is to find fissures or cracks, I am unsure if you can simulate this easily. The permanent deformation can be easily seen by comparing your FEM stress to the yield stress of the material, once you already have this value. I recommend posting your doubts in English so anyone can help you (here, for instance, one would need to speak Portuguese to see the procedure goal clearly).

CalculiX does have a crack propagation module, not as advanced as Nasgro or other commercial software and it may be expensive to achieve a valid model to simulate this. Probably the test is going to be the cheapest way.

As others stated, you need to use non-linear analysis, and your results need to be carefully validated due to the nature of the problem (material nonlinearity, contact nonlinearity, and geometric nonlinearity!). Good luck.

Reading many reference document of HDPE, the crack is related to material degradation subjected to chemical attack and seasoning called environment stress crack. Since crack are due to tension stress, so in above case as shown is required to review in principal positive stress direction.

From my personal view. Material strength in cracked limit may not homogenous as another type e.g steel, variation depend on chemical liquid or particle attack in position or direction. Also, seasoning effect.

I’m not really familiar with HDPE material regarding to code regulations, may it give some guidance related to allowable stress in cracking similar to concrete i frequently reviewed. Still these all steps only at level of preliminary investigation with low accuracy, required specific advanced damage material models to predict the behaviour and ultimate capacity.

True, Brazilians who work with this, does not reach 1%. (rsrs)
My goal with the image is just to illustrate the model I want to achieve, obviously English is the best option for communication here.
My objective is not to simulate the crack, but to determine a model to be able to observe the maximum load that the profile and load support.
I am developing a new profile and want to simulate this load.

Hey guys.
I tried several ways to create a model to simulate displacement (flattening) of the profile, without success.
Thanks if anyone knows a tutorial that helps me.
Model is not a problem, it’s the parameters that stop me.
Thanks

What particular issues did you encounter ? We can try to help you solve them but you would have to share your progress so far - at least screenshots and detailed description, possibly PrePoMax file.