Goodevening, I have tried a simulation on the same metallic piece both with ansys and PrePoMax. The point is I get a 4% error for what concerns deformations, which is accetable, instead I get more than 15% error among the results of mieses and buckling factor, which to me is too much. I may have set PrePoMax the wrong way since the simulation took ~100 sec wrt ~360sec with ansys. I have a pdf with all the configutations I have set but I cannot upload them since I am a new user, if anyone thinks can help me I will be happy to share also my documentation.
Best Regards.
But you are talking about two different analyses, right ? Because linear buckling simulations give only buckling factor and mode shape. Other values (like deformations and stresses) are normalized and therefore not physical.
You can use some hosting website and paste the link here.
Yes, I have done a bunch of tests. WeTransfer - Send Large Files & Share Photos Online - Up to 2GB Free
Your mesh is definitively not adequate.
The smallest wave pattern in the first buckling mode should contain a minimum of 6 elements in the wave direction. You can see the approximate size in the Ansys model.
Your triangles will not capture it. Some of them almost have the size of the wavelength. I have refined just in the area of interest (Base) and overall numbers are much better.
I would also review all the material parameters and compare element integration scheme between models.
| RESULTS ANSYS | RESULT ccx | RESULT ccx REV1 | ||
|---|---|---|---|---|
| DEFORMATION MAX | 278 | 265 | 270 | mm |
| STRESS MISES | 86 | 73 | 85 | Mpa |
| PRINCIPAL MAX | 116 | 97 | 102 | Mpa |
| BUCKLING FACTOR | 51 | 93 | 54 |
I guessed the error was related to density of the mesh. I have changed it and now I am getting much better results. I would like to understand if it is possible to get the same mesh you have sent with PrePoMax or I have to stick with triangular mesh and deal with triangle density by tuning the parameter available in the Meshing pop up window. Thank you.
My mesh was made by hand. For these simple geometries, by the time I draw the step, export, import, set the mesh parameters, try to adjust them and desperate , the mesh is done, and I have finished my coffee. You could give it a try to Gmsh. Some people use Salome here too. Both freeware.