Description:
pycalculix is a Python 3 library to automate and build finite element analysis (FEA) models in Calculix.
Meshing uses Calculix or GMSH.
Website: http://justinablack.com/pycalculix/
Source Code: https://github.com/spacether/pycalculix
Documentation: http://spacether.github.io/pycalculix/pycalculix.html


Usefull applications of Pycalculix:
-Trade studies for plane stress, plane strain, or axisymmetric parts
-Quick Kt analysis of 2D geometry
-Learning finite element analyis (FEA) and Python


Folder layout:
The folders of this project are laid out to allow me to distribute it on pypi.
Pypi link: https://pypi.python.org/pypi/pycalculix
Note: the main body of pycalculix code is in pycalculix/feamodel.py module


Notes, Cutting Areas:
I built a chunker in python which tries to cut big areas (> 5 sides) which
cgx can't mesh into smaller areas (<= 5 sides) which are meshable in cgx.
The chunker may not always be able to cut areas correctly.


License:
See LICENSE.txt (GPL v2)


Creator:
Justin Black, justin.a.black[at-sign]gmail[dot]com
Initial Release: December 2014


Elements Supported:
Axisymmetric, plane stress, and plane strain elements are supported.
First and second order triangles and quadrilaterals are supported.
  First order elments only have corner nodes
  Second order elements have corner and midside nodes
Second order elements produce more accurate results
Setting element divisions on lines is supported


Geometry Building:
One can build separate parts made of points, lines, arcs, and areas.
Straight lines and arcs are currently supported.
One can draw a part made of straight lines, then smooth out corners by adding
arcs with the part method: part.fillet_lines(L1, L2, arc_radius)
The new arc will be tangent to both adjacent lines.


Loading:
Force loading
Constant pressure
Linearly varying pressure (water pressure)
Gravity 
Rotational speed forces
Displacement constraints
Loads are stored on geometry primitives (points lines, areas) and can be
applied before or after meshing.


Getting Started:
1) To run a pycalcuix file you have to have pycalulix installed,
see Installation below
2) The you can then write your own pycalculix programs or run one of the example
files in the eamples folder on github:
https://github.com/spacether/pycalculix/tree/master/examples
3) To run a file:
WINDOWS:
Graphical user interface:
  Double click the file: if the .py extension is associated correctly you can
  double click it to run the .py program
Console:
  1) cd into the directory with your .py file in it
  2) type:
  python the_program.py
  where the_program.py is the name of the file that you are running
  This assumes that python3 is your active python installation

LINUX:
Console:
  1) cd into the directory with your .py file in it
  2) type:
  python3 the_program.py
  where the_program.py is the name of the file that you are running


Files Produced:
Meshing and solving are done in the background using cgx or gmsh for meshing,
and Calculix ccx for solving.
Files Used:
*.fbd (Calculix cgx gemetry file)
*.inp (Calculix solver input file, or mesh definition)
*.geo (Gmsh geometry file)
*.msh (Gmsh native mesh file)
*.frd (Calculix ccx nodal results file, values are at nodes and were created
       by interpolating element integration point results back to the nodes)
*.dat (Calculix ccx element results file, includes integration point results)


Installation:
pycalculix requires the below software:
  Python3+
  Numpy (S1,S2,S3 calculation)
  Matplotlib (plotting)
  Calculix (solving)
  Gmsh (meshing)

EASIEST INSTALLATION:

WINDOWS:
1) Install Anaconda* python 3.4:
http://continuum.io/downloads#py34  
This includes required libraries like numpy and matplotlib.
Note:
64-bit:
    This is an easier option for 64 bit systems because the binaries of the
    other libraries are harder to find.
32-bit:
    *Rather than installing anaconda you can just install python 3+ from the
    python site:
    https://www.python.org/downloads/release/python-343/
    When you install pycalculix in the next step below, the required libraries
    will autoinstall on your system.

2) In a console window, type:
pip install pycalculix
Note: This installs the calculix and gmsh programs in sub-folders in the python
    pycalculix folder.
    Running these included binaries from pycalculix only works for windows.

3) You are done! See 'Getting Started'

LINUX
(assumes Ubuntu 14.04)

1) Install required prerequsisites. In the console enter:
sudo apt-get install python3-pip python3-matplotlib gmsh
Note: this installs
    pip (a python library downloader) for python 3
    python3 matplotlib (the required matplotlib library needed for plotting)
    gmsh (software needed to mesh you FEA models)

2) Install both calculix ccx and calculix cgx for your architecture (32 or 64 bit)
Ubuntu 14.04.1 (Trusty)
--------
32-bit:
--------
ccx: https://code.launchpad.net/~cae-team/+archive/ubuntu/ppa/+build/7043228/+files/calculix-ccx_2.7-0%7E1%2B6%7Eubuntu14.04.1_i386.deb
cgx: https://code.launchpad.net/~cae-team/+archive/ubuntu/ppa/+build/7043230/+files/calculix-cgx_2.7-0%7E1%2B3%7Eubuntu14.10.1_i386.deb

--------
64-bit:
--------
ccx: https://code.launchpad.net/~cae-team/+archive/ubuntu/ppa/+build/7043227/+files/calculix-ccx_2.7-0%7E1%2B6%7Eubuntu14.04.1_amd64.deb
cgx: https://code.launchpad.net/~cae-team/+archive/ubuntu/ppa/+build/7043229/+files/calculix-cgx_2.7-0%7E1%2B3%7Eubuntu14.10.1_amd64.deb

3) In the console window type:
pip3 install pycalculix

4) You are done! See 'Getting Started'


Separate Installs:
Install Python 3+: https://www.python.org/downloads/release/python-342/
Install numpy: http://sourceforge.net/projects/numpy/files/NumPy/1.9.1/
Install matplotlib: http://matplotlib.org/downloads.html
Install Calculix: http://www.calculix.de/
    Linux Version: http://www.dhondt.de/
    Windows Version: http://www.bconverged.com/download.php#calculix
Install Gmsh: http://geuz.org/gmsh/#Download
pip install pycalculix
Then pass locations to ccx, cgx, and gmsh per the example on the
pycaculix site: http://justinablack.com/pycalculix/

Anaconda:
	An installation package that includes Python and many python libraries
	Anaconda includes the below Python3+, Numpy, and Matplotlib.
	If you are a Python beginner, I suggest downloading and installing it
	rather than the separate installers.
	Url:
	http://continuum.io/downloads#py34	

Optional Software:
Suggested IDE (program to edit and run python programs):
Wing IDE:
	http://wingware.com/downloads/wingide-101

Version Updates:
0.9.3
    ADDED: Import CAD geometry from dxf file
        See pycalculix.CadImporter
    ADDED: Element results plotting added
        Element results plotting:   pycalculix.Problem.rfile.eplot()
        Nodal results plotting:     pycalculix.Problem.rfile.nplot()
        Number Formatting:
            Strain results now use scientific formatting
            Others use nearest 10**3 suffixes
        Max and min values now listed above the colorbar
    ADDED: method to draw an arc by swept angle in degrees
        part.draw_arc_angle(degrees_ccw, center_x, center_y)
    ADDED: min_val and max_val can now be passed to eplot and nplot
        This lets the user set the results range that they want to see:
        min_val <= colored results <= max_val
        Values under and over are greyed out, darker under, lighter over
    ADDED: internal holes in parts
        One can make circular holes, or draw complicated holes.
        See example 7
    ADDED: Added set_ediv method to FeaModel class.
        This method sets the number of elements on a line.
        line.set_ediv still works.
    ADDED: Robust selection object: feamodel.view
        This object is feamodel.view Most important methods are:
        view.select_all, view.select, view.allsel_under
        All plotting now uses the current selection set
    SYNTAX: updated how parts, materials, problems are made
        Make part: 
            pycalculix.FeaModel.make_part or pycalculix.Part    
        Make material:
            pycalculix.FeaModel.make_matl or pycalculix.Material    
        Make problem (previously called model):
            pycalculix.FeaModel.make_problem or pycalculix.Problem
        Make Results File:
            pycalculix.Problem.rfile or pycalculix.ResultsFile(problem)
    FIX: Plotting fix, closing triangles in the correct direction in matplotlib
    DOC: All code separated into modules for clarity.
    DOC: Docstrings added to all classes + methods + functions
    PLOTTING: Closed areas are now filled in yellow when plotting geometry.
    PLOTTING: Signed line names are shown and internal to the area.
    BACKEND: Implimented signed line and signed arc class.
            Pressures can now be applied on these signed lines.
            Many methods and variables made private to clean up name space.

TODO:
Add tutorial videos
Update pdf
Improve Pylint Scores:
    feamodel        9.28
    geometry        9.02
    results_file    9.75
    part            9.64
    selector        9.89
    mesh            9.66
    loads           9.80
    cadimporter     9.71
    problem         9.82
    base_classes    9.51
    components      10.0
    material        10.0
    environment     9.39
    connectors      9.57

Future Goals:
-CAD import of: brep, step, iges
    can make geo files with gmsh:
        gmsh freecad_part.iges -o out_iges.geo -0
        gmsh freecad_part.brep -o out_brep.geo -0
        gmsh freecad_part.step -o out_step.geo -0

            Importing the geo file:
            Do points need explicit numbers? no, store them in a dict
                points[geo_str] = point
            Need to convert spline to arcs if it's a circle or arc >= 180
                Will need to delete some points + make center point
-Ability to make a new field (% yield etc)
-Double check effective strain calculation:
    http://orange.engr.ucdavis.edu/Documentation12.0/120/ans_thry.pdf 
    pg 23 + 24
    https://support.tnodiana.com/manuals/d944/Analys/node405.html
    https://books.google.com/books?id=70vvzjngyQEC&pg=PA21&lpg=PA21&dq=equivalent+strain+principal+strain&source=bl&ots=bPj4dHfddy&sig=X6MAdyeq34X9uNQRZ1poKXHZK9c&hl=en&sa=X&ei=lr2_VL_lM4q4ggS7loHICw&ved=0CFwQ6AEwCQ#v=onepage&q=equivalent%20strain%20principal%20strain&f=false
-Is my element stress calculation correct? Should it be an average, or a centroid val?
    http://mostreal.sk/html/elem_55/chapter2/ES2-2.htm
    http://orange.engr.ucdavis.edu/Documentation12.0/120/ans_thry.pdf#page=536&zoom=auto,32.4,582.228
-Add area chunker around arcs
-Add part offset function to offset a line and close an area
-Add contact between parts
-Add compression supports
    model.make_compr_support('L5', 10)
        make new part with new line loop, not closed, new line
        set ndivs on both lines (only needed if before meshing)
        make connector object
            pre mesh: make gap elements after meshing
            post mesh: clone the existing nodes with new node numbers, make gap eles

-Reaction force fix?
-Coupling nodes under points and lines ("gluing")
    This would allow 'correct' stresses for knock up at discontinuities
-Add struct-thermal and thermal support
-Order faces under slines to be sequential so they can be output later
-Order nodes under slines to be sequential so they can be output later
-Add mp4 maker
-Bolted joint example perhaps, nodal thickness on bolt and nut areas
-Interactive selection?
-Face plotting?
-Aluminum can model?
    -https://www.youtube.com/watch?v=hUhisi2FBuw