Generate Thick Fibers with STL File

Generate random fibers taking into account their diameters and creates STL file

This tool generates randomly oriented fibers. Then, STL file is created for the generated fibers. The algorithm takes into account fibers diameters for ovelap checking with other fibers. Example files are provided for the simulation of notched beam "Example_Beam.m" ,cylinder "Example_Cylinder.m", and cube "Example_Cube.m".

Important Notes:

1-This tool requires stlwrite function (tested with version 1.9.0.0). The user should download it and put the file in the same folder of this tool. The link for stlwrite function is:

https://www.mathworks.com/matlabcentral/fileexchange/20922-stlwrite-write-ascii-or-binary-stl-files

2-Newer versions of matlab have builtin function stlwrite function introduced in R2018b. The user can use it instead of the function in mentioned above by replacing the following line in Fiber2STL.m:

stlwrite(Filename,FF,VV);

with:

TR = triangulation(FF,VV); stlwrite(TR,Filename);

functions:-

[Nodes_Fibers, Fibers]=Generate_Fiber(x,y,z,L,N,DFiber,Orientation,Ndiv);

Plot_Fiber(x,y,z,Nodes_Fibers,Fibers,DFiber);

Fiber2STL(Nodes_Fibers,Fibers,DFiber,Filename);

Input:

x,y,z: as vectors defining the specimen dimension. x and z are vectors defining a polygon section in xz plane and y=[ymin ymax] is boundaries of the extrusion of the polygon

L: Length of fibers

N: Number of fibers

DFiber: Diameter of fibers

Orientation: can be either:-

-For aligned fibers Orientation=[l m n] where l,m, and n are the direction cosines of the fibers orientation in x,y, and z directions, respectively.

- For random fibers Orientation=[] (empty)

Ndiv: Number of fiber mesh divisions

Filename: name of the STL file with the extension.

Output:

Nodes_Fibers: ((Ndiv+1)*N,3) matrix of fibers nodes coordinates.

Fibers: (N,2) matrix of the two nodes indices connecting each fiber segment.

references

[1] Unger, Jörg F., and Stefan Eckardt. "Multiscale modeling of concrete." Archives of Computational Methods in Engineering18.3 (2011): 341.

[2] Fang, Qin, and Jinhua Zhang. "Three-dimensional modelling of steel fiber reinforced concrete material under intense dynamic loading." Construction and Building Materials 44 (2013): 118-132.

[3] Islam, Mohammad, Gregory J. Tudryn, and Catalin R. Picu. "Microstructure modeling of random composites with cylindrical inclusions having high volume fraction and broad aspect ratio distribution." Computational Materials Science 125 (2016): 309-318.