Id: Data of following publication

title = "Development of a Geometric Modeling Strategy for the Generation of Representative Unit Cells in 2D Braids",
journal = "Composite Structures",
volume =" 348",
pages = "118503",
year = "2025",
doi = "10.1016/j.compstruct.2024.118503",
author = "José Rothkegel, Benjamin Renson, Michael Bruyneel, Ludovic Noels"

Data doi on 10.5281/zenodo.10829042

pyRVE

Python Code for Geometrical Generator for Braided Composites RVE

pyRVE is a code written in Python using the GMSH API that generates the Representative Unit Cell (RUC) of braided composites. It allows the generation of the RUC of triaxial braided for Diamond and Regular patterns.

Requirements

To run, it requires:

• The GMSH Python API, which must be built with OpenCascade support.
  • Choose a local installation directory; CMAKE_INSTALL_PREFIX=$HOME/local/gmsh, and GMSHPY_INSTALL_DIRECTORY=$HOME/local/gmsh e.g.;
  • Make that directory part of your export PYTHONPATH=$HOME/local/gmsh/lib:$PYTHONPATH.
  • After compiling use make install.
• The CM3 app dG3D if the final RVE homogenized solution is needed (https://gitlab.onelab.info/cm3/cm3Libraries).
• Make sure that the latest version of OpenCascade (OCCT) is used. Current used version in occt-V7.8.0.

Usage

File Structure

A typical run case must have a file structure, where:

• brd: the files .brd and .brep are located here. The .brd is a backup of the braidClass instance used in the model saved using pickle, the .brep is the Boundary Representation file that can be opened with GMSH.
• csv: the .csv file saved here is the initial output of the code. It contains the actually used dimensions and the final cover factor of the braid.
• data: It contains .csv files with the material properties and the dimensions of the tows. The original model dimensions are read from here.
• dir: In the case of running the RVE homogenization, the directions of the tow fibers are stored here. They are saved for post processing.
• msh: the mesh file .msh obtained after the geometry geneartion is stores here.
• png: in the case of automatic post processing, png files are stored here.
• res: this folder is used to store the homogenization results. They have to be moved here.
• stp: if acitvated, a .stp file of the geometry is stored here
• svg: the projection of the geometry on the x-y plane is stored here.
• vtk: A copy of the mesh file without the matrix mesh is sotred here as a `.vtk`` file.

How to Run

We will consider the current file structure to run the example in 000_Base. To run the code, it can be called from the command prompt as

python3 ../../source/mainRVE.py --name <i> --pattern <pattern>

In this case, the --name refers to the index that will be given to the model, where <i> must be changed to an integer and --pattern refers to the wanted pattern to be used, where <pattern> must be changed to either dia or reg.

Note: --namecat can also be used to reproduce the regular pattern benchmark of the paper. In that case, the volume fraction of fiber in the tows is hard coded as the provided value in the reference (i.e. 0.86). For other cases, the volume fraction is evaluated from the tow cross-sections.

Note: mainRVE.py must be accesible from the directory where the case is being run. This example shows the usage of the current file structure.

All Command Line Options

The code can be run using further options that serve different purpouses, some serving pre processing needs and other serving run administration. The different command line options are:

• Required:
  • --name : it gives a suffix to the run model. It is usually an integer.
  • --pattern : indicates the type of pattern to be used to build the geometry. The two current options are dia for diamond and reg for regular.
• Optional
  • -dG3D: it indicates that the homogenization of the generated RUC is to be perfomed.
  • -GMSH : it indicates that GMSH must be open upon competion of the generation of the mesh.
  • -loadModel : it will try to load a premade model. It will ignore --pattern.
  • --rndPrm : it will generate randomized geometrical parameters. It can be used to generate batches of results. It takes an argument that can be 2, 4 or 6. Currently, 2 gives a random value for s_axial and theta, 4 randomizes the same as 2 and adds h_axial and h_bias, and 6 randomizes the same as 4 and adds w_axial and w_bias.
• Pre-Processing
  • -refCF: it tells the code to generate a grid of values for s_axial and theta where only the cover factor is obtained. It is meant for posterior graphing purposes.

Examples

Following the run options, a few examples are indicated

• A basic mesh generation run for the basic data, considering a regular pattern, for a model named 2:

python3 ../../source/mainRVE.py --name 2 --pattern reg

• The generation of the cover factor data and export, considering a regular pattern:

python3 ../../source/mainRVE.py --pattern reg -refCF

• A run for the modified basic data, where the 2 parameters are modified randomly, considering a regular pattern, for a model named 2:

python3 ../../source/mainRVE.py --name 2 --pattern reg --rndPrm 2

• A run, where model 2 already exists in brd folder but not the .msh and .vtk files:

python3 ../../source/mainRVE.py --name 2 -loadModel 

Code Structure

The code is implemented into Python files, where mainRVE.py runs the whole code. The files are:

• Braid:
  • braidClass.py :
  • bzrPairClass.py :
• Geometry
  • bezrClass.py :
  • bilnClass.py :
  • patchClass.py :
  • pntSetClass.py :
  • pointClass.py :
  • sctnClass.py :
  • stripeClass.py :
  • surfClass.py :
  • surfOffClass.py :
• Material:
  • chamis.py :
• Tools:
  • dataIO.py :
  • postDirection.py :
  • tool.py :
  • toolData.py :
• curveClass.py :*