Hi
It seems that something is wrong with symmetry transformation in PrePoMax. I created a model to simulate a hollow plate under tension. Due to the X and Y symmetry planes only one quarter of it has been modeled as follows:
When the U2 displacement is expanded through the whole model, surprisingly you get positive value for the displacement on the lower part of the plate:
The same issue is for U1 displacement:
The deformed shape is correct.
To me, the deformation plots and both the U1 & U2 displacement results make sense. Perhaps I have missed something.
You mention that this is a “hollow” plate but from the plan view you have provided we can’t tell the section profile that you have modelled. Are you expecting different deformation because of the “hollow” section ?
I think that I understand your point now…
These results are only associated with the ‘1/4 model’ the you analysed (top-right), even though you have asked PreProMax to display the X & Y symmetry plots. So, in fact the results are displayed in ‘relation to the symmetry plane’ displayed. Hope this makes sense.
It seems that this issue is not just for displacement components. I think that each quantity that its positive value depends on the coordinate system is in the same boat. For instance, you can see the contour of the shear stress S12 in the following figures:
Complete Model:
Symmetric Model:
still applicable for shear stress, since different sign has no consequence.
symetric feature is commonly used for model presentation only, maybe an option to displays only deformed part of mirroring can be useful. The contour is turned off, except the original models,
When the shown field is not quarter-symmetric to the cutting planes too (here S12), you can not get the full range from this model. For a representation of the full stress range of S12, you need a half-model (but still then, mirror the upper half to the bottom is not correct because the field is not symmetric to these planes).
So comparing these pictures is misleading - the colour bar extends over a completely different range when hiding the full model:
Thanks for the discussions. If I want to conclude them for myself, the current version of the symmetry transformation just mirrors everything along the symmetry plane. Hence, it is not applicable for all kind of the output contour results.
I recognized the same issue with my chain model. That is why I have not shown the following deformation plot. Because the numbers at the legend showing only the results of the original quarter model and not the numbers for the full plot.
If you are transform the results only perpendicular to the force direction then the values are still okay.
@FEAnalyst, Thank you.
I think this is a symmetry transformation.
I see Abaqus has the same solution as PrePoMax. But in Paraview, the solution is better. So, we might apply the solution from the Paraview. And add an option to turn it on or off in the Transformation settings.
