Hello.
It would be nice to have a more complete material library, and not just ABS and STEEL.
Thank you very much
Giovanni Di Maria
right, CalculiX has many material type. integration with MFRONT libraries also makes it rich. however, it seems the implementation may large enough to be supported.
may additional feature of costumed material with simple text input is enough to cover the complexity of large variant and parameters.
alternatively is it possible to add manually by editing of material.lib files?
Due to the variety of materials used in analyses, libraries like this are primarily meant to be filled by users. For example, Abaqus has a material library that is empty by default. PrePoMax on the other hand offers some exemplary materials for a start. More variants could be added but it’s not always easy to find reliable sources for all the necessary properties. Maybe we could help collect the data for further material examples.
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Here’s a quote from PrePoMax User’s Manual:
The library file is a text-based file that can be edited using any .txt editor, like Notepad++. It is assumed that all material data is stored using the mm, ton, s, °C unit system. But the library file is not meant to be edited this way since it is created directly from the material objects using JSON serialization and thus not easily readable. The library is meant to be edited using the PrePoMax built-in material editor.
i tried to understand these JSON format, but it seems not a general ways to described large variance input parameter of material type.
below input parameters fixed by material.lib JSON format files,
- Density
- Slip wear
- Elastic
- Plastic
- Thermal expansion
- Thermal conductivity
- Specific heat
not possible to add another (e.g Hyperelastic, Deformation plasticity, Tension/Compression only) material type by editing these lib files. it’s due to different input parameters needed, although Keyword Editor features could tackle this task easily.
These material behaviors are not yet supported so adding their properties to the library could cause issues with the material editor. However, you can define them using the Keyword Editor, as you’ve mentioned.
As @FEAnalyst explained the material library files are not meant to be edited by text editors. They are meant to be edited using the built-in material library editor. Thus, only material properties supported by PrePoMax are supported inside the material library file.
I totally agree with the approach of the user having to specify its materials! But still I really liked it, that PrePoMax had some basic materials already prepared when I used PrePoMax for the first time. So I could just go forward with my first simulations. 
In the meantime I have added some more polymer materials (https://www.campusplastics.com/ is a good source). Once you know how to do it, it is really user friendly to do it within PrePoMax. I do not want to edit the lib-file by hand. I struggled a little bit with filling the PLASTIC stress strain table. Somehow copying the table from excel into PrePoMax is not really working and so I had to type in every value. Saving a txt.-File from excel and load it into PrePoMax did the job.
Step after step I’m updating the basic material library. For plastic properties I use DNV RP C208 material model for S235 and S355. S275, widely used in Italy, the material stress/strain curve is proposed.
For Prepomax use the left table
Reference: DNV RC P208: Determination of Structural Capacity by Non-linear FE analysis
4.7.5 Stress - strain curves for ultimate capacity analyses
More awesome would be classic Eurocode Curves.
Excuse me but on which part of Eurocode did you find stress/strain curve?
EN 1993-1-5
Example simple S250 with 190promile:
5% plastic strain limit is only a recommendation but not a need:
The DNV RP P208 is definitely an interesting and easy-to-understand recommendation with nice examples.
The linear hardening curves shown above must be from an older version; in later versions, the curve progression is multilinear and described by the parameters K and n (ep, here i used 0.2, is uncommitted).
awesome!
Questions is just if German “Prüfstatiker–>structural verification engineer” will accept it…
