External CAD (NX) Integration
==============================

PyFemtet allows parametric optimization even for analysis models created with external CAD (NX) and imported into Femtet.


Sample File
------------------------------
.. note::

   Place the 
   :download:`sample model<../_temporary_sample_files/cad_ex01_NX.prt>`
   and
   :download:`sample project<../_temporary_sample_files/cad_ex01_NX.femprj>`
   in the same folder.
   Keep the project open in Femtet, then double-click on the
   :download:`sample code<../_temporary_sample_files/cad_ex01_NX.py>`
   to execute it.


Details as a FEM Problem
------------------------------

.. figure:: NX_ex01_analysis.png
   :width: 450
   
   Appearance of the Model (and Analysis Conditions)

- fix ... Fully Fixed
- load ... Load in the -Z direction (1N)
- mirror ... Symmetrical to the XZ plane


Design Variables
------------------------------

.. figure:: NX_ex01_model_dsgn.png
   :width: 450
   
   Appearance of the Model Section (and Design Variables)

============== ============
Variable Name  Description
============== ============
A              Web Tickness
B              Flange Tickness
C              Flange Bending
============== ============


Objective Function
------------------------------

- Maximum Displacement in the Z direction (set to 0)
- Volume (minimize)


Sample Code
------------------------------

.. literalinclude:: ../_temporary_sample_files/cad_ex01_NX.py
   :language: python
   :linenos:
   :caption: cad_ex01_NX.py


Execution Result of the Sample Code
----------------------------------------

.. figure:: NX_ex01_result.png
   :width: 450

   Execution result of NX_ex01.py. The horizontal axis is von Mises stress, and the vertical axis is mass.

After the 20 trials, a Pareto set of von Mises stress and mass is obtained.


.. note::

   Results may vary slightly depending on the versions of Femtet, PyFemtet, and the optimization engine it depends on.