hex2rdl

Below is a demonstration of the features of the hex2rdl function

Contents

Syntax

[Ep,Et,Vs]=hex2rdl(Eh,V,inputStruct);

Description

This function creates rhombic-dodecahedron lattices and diamond lattices from hexahedral input meshes.

clear; close all; clc;

Plot settings

fontSize=25;
faceAlpha1=0.25;
edgeWidth=3;
markerSize=25;
cMap=gjet(6);

Examples

EXAMPLE 1: Converting a hexahedral element to tetrahedral elements

Creating an example hexahedral element set

testCase=2;
switch testCase
    case 1 %Cube
        V=[0 0 0; 1 0 0; 1 1 0; 0 1 0; 0 0 1; 1 0 1; 1 1 1; 0 1 1;]-0.5; %nodes
        Eh=1:8; %Element
    case 2 %Subdivided cube
        V=[0 0 0; 1 0 0; 1 1 0; 0 1 0; 0 0 1; 1 0 1; 1 1 1; 0 1 1;]-0.5; %nodes
        Eh=1:8; %Element
        [Eh,V]=subHex(Eh,V,1);
    case 3 %Sphere hex mesh
        sphereRadius=2;

        %Creating sphere mesh
        optionStructSphereHexMesh.sphereRadius=sphereRadius;
        optionStructSphereHexMesh.coreRadius=sphereRadius/3;
        optionStructSphereHexMesh.numElementsMantel=2;
        optionStructSphereHexMesh.numElementsCore=4;
        optionStructSphereHexMesh.makeHollow=0;
        optionStructSphereHexMesh.outputStructType=2;
        [meshStruct]=hexMeshSphere(optionStructSphereHexMesh);

        % Access model element and patch data
        V=meshStruct.nodes;
        Eh=meshStruct.elements;
end
nSubPenta=1;

strutThickness=0.1;

F=element2patch(Eh,V);
d=mean(patchEdgeLengths(F,V));

shrinkFactor=strutThickness./(d.*(sqrt(2)./2));

inputStruct.latticePhaseType=1; % 1 = "bubble" centred, 2 = vertex centred, 3 = nested
inputStruct.latticeType=2; % rhombic-dodecahedron (1) or Diamond (2)
inputStruct.shrinkFactor=shrinkFactor;
inputStruct.removeNonConnected=1;

[Ep,Et,VT]=hex2rdl(Eh,V,inputStruct); %Create the mesh
[Ep,VT]=subPenta(Ep,VT,nSubPenta,3); %Sub-divide pentahedra

Visualization of lattice meshes

% Convert tetrahedra and pentahedra to faces
[Ft]=element2patch(Et,[],'tet4');
[Fp]=element2patch(Ep,[],'penta6');

% Convert original hexahedra to faces
[Fh]=element2patch(Eh,[],'hex8');

cFigure; hold on;
hp1=gpatch(Fh,V,'w','k',0.25,edgeWidth);
hp2=gpatch(Ft,VT,'bw','k',1,1); % Color for flip type
hp3=gpatch(Fp,VT,'gw','k',1,1);
legend([hp1 hp2 hp3(1)],{'Input hex mesh','Tetrahedra','Pentahedra'});
axisGeom(gca,fontSize); camlight headlight;
gdrawnow;

GIBBON www.gibboncode.org

Kevin Mattheus Moerman, [email protected]

GIBBON footer text

License: https://github.com/gibbonCode/GIBBON/blob/master/LICENSE

GIBBON: The Geometry and Image-based Bioengineering add-On. A toolbox for image segmentation, image-based modeling, meshing, and finite element analysis.

Copyright (C) 2006-2022 Kevin Mattheus Moerman and the GIBBON contributors

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Published with MATLAB® R2023a