Enhancement Feasibility

Hello Group/Developers,
Recently we carried our elastic plastic analysis on torsional bar to find the residual stress. More details are available at https://youtu.be/Zw97RI4TgYM.
The simulation was further compared with Abaqus/Test results (reference) in a publicly available paper. While the results agreed nicely, it is observed that following improvement could make Calculix even better.

  1. The contour plots are much smoother in reference, while in Calculix it appears bit patchy. Is it possible to improve on smoothness?. If there is any work around or something we missed any available methods, please direct us on the available options.
  2. While we see it is possible to calculate the crack initiation life or fatigue safety factor, externally, native options can be very helpful. Can this be added as a feature? For example Dang Van criteria? We are aware crack propagation life can be calculated natively though.

Thanks for this great tool once again.
Best Regards,

It might be better to create feature requests directly here: Issues · Dhondtguido/CalculiX · GitHub

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Thank you for the suggestion. It has been posted.

As an aside, it is possible to create a regular hex mesh of a cylinder in cgx. Here you can see how to do it.

Part of it is because of the color map.
The calculix color map is very different from the abaqus one; it has more distinct colors.
You could also play with the number of steps in the calculix colormap.

Color maps like viridis or coolwarm have smoother transitions between the colors, IMO. Coolwarm works especially well if you set min and max to the same magnitude using the mm command.

Another thing to take into account is the mesh size. Try halving the mesh size and see how that looks.

You could also view the CalculiX results using e.g. Paraview, if you like fancier pictures.

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Thank you for the reference. The choice of selecting meshing tool was to ensure scalability. However, it would be interesting to know if it is possible to obtain superior quality Hex mesh, when the mesh is prepared in cgx than creating the same from other open source tools like gmsh and Salome.

We tried the suggestion, but for the case that we are in consideration, we couldn’t observe any difference. Only the color change was observed. The contour pattern remained same.

Unfortunately, the time taken for solution is already half core hour and the suggested mesh size can significantly increase run time,it would be challenging to run a larger model. One of our objective is to keep the model as light as possible without compromising accuracy. If you take a look at the result comparison, the results are reasonably close and acceptable.

We need to be bit clear that, the patchy appearance is not because of averaging and/or interpolation issue, so that the results can be dependable.

Sure, but we still feel a native enhancement could be very handy for the above mentioned reason.

We once again extend our appreciation for your insights.

Anyways, we have already posted the enhancement request. Hope it would be take up some day!!.

Beat Regards,