Typestate API programming idea

API & Interfaces
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1

Good day again,

As I am currently in the process of creating a type statics for a connection and repeatedly entering and reviewing processes, I came up with the idea to program something for this.

In my previous attempts with the API, I always coded structures or modeling tasks, and here lies the difference or the reason why I am asking for advice this time,

because:

I want to have the possibility to automatically generate load cases for an existing, fully modeled model, evaluate the comparative strain in these, and depending on the result, delete or save them, that is:

  • A load Fx (X) with a starting value of 40 kN is applied at the rigid plane of the connection and a moment MY (Y) with the starting value of 80 kNm
  • The model should calculate according to first-order theory and then evaluate the comparative strain in the isotropic areas; if this is less than 5 per mille, the penultimate created load case should be deleted and a new one created with a moment MY (Y+10), i.e. 90 kNm
  • If the evaluation of the limit strains is greater than 5%, the loop breaks and is now initiated with an Fx (X+10), and again the maximum corresponding MY (Y) is determined.

I like programming the loops myself very much; it would be great to have commands by which I can:

  1. calculate an existing model with load case X
  2. then have the script automatically evaluate the results (if max epsilonvMises > 5 then…)
  3. then have the script create a new load case (I can manage this so far)
  4. have the script restart the calculation automatically through the loop for the new load case without manual start of the script
  5. have the script also delete load cases (so that when I go to the computer the next day, I immediately see only the relevant limit cases)

I would be very grateful for any lines of code, example codes, similar scripts, etc., or further explanations, as I could simply let the PC run over the weekend or otherwise in the background and get my work done instead of constantly re-evaluating models from scratch + creating load cases + creating Excel sheets, etc. An evaluation of the connection addon itself (integrated function) is unfortunately not an option, because even though the base model originated from its input, modifications had to be made that cannot be correctly represented there and had to be corrected in the submodel.

Thank you very much.

Best regards,

Nick Böttcher

3

Hello Nick,
nice to hear that you want to use our API so intensively. :slight_smile:

To connect to an existing model and calculate a specific load case, you can use the following two commands:

rfem_app.get_active_model()
rfem_app.calculate_specific(
loadings=[
        rfem.ObjectId(
            no=2,
            object_type=rfem.OBJECT_TYPE_LOAD_COMBINATION
        )
    ],
    skip_warnings=True)

To evaluate the results, you can use the functions "get_results" or "get_result_table". Depending on your needs, you can also filter the results directly:
https://apidocs.dlubal.com/source/rst_examples/rfem/results/results_filtering.html

With the function "delete_object" you can delete individual load cases. Alternatively, you could first collect the non-critical load cases and then delete them bundled via "delete_object_list":
https://apidocs.dlubal.com/source/rst_methods/rfem/delete_object_list.html

Best regards,
Rebecca Göbel

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6

Thank you very much again!

An absolute majority has now been accomplished thanks to the links and many example codes!

Best regards,

Nick

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