DEMO_abaqus_0001_cube_uniaxial

Below is a demonstration for:

Contents

Keywords

clear; close all; clc;

Plot settings

fontSize=20;
faceAlpha1=0.8;
markerSize=40;
lineWidth=3;

Control parameters

% Path names
defaultFolder = fileparts(fileparts(mfilename('fullpath')));
savePath=fullfile(defaultFolder,'data','temp');

% Defining file names
abaqusInpFileNamePart='tempModel';
abaqusInpFileName=fullfile(savePath,[abaqusInpFileNamePart,'.inp']); %INP file name
abaqusDATFileName=fullfile(savePath,[abaqusInpFileNamePart,'.dat']); %DAT file name

%Specifying dimensions and number of elements
cubeSize=10;
sampleWidth=cubeSize; %Width
sampleThickness=cubeSize; %Thickness
sampleHeight=cubeSize; %Height
pointSpacings=2*ones(1,3); %Desired point spacing between nodes
numElementsWidth=round(sampleWidth/pointSpacings(1)); %Number of elemens in dir 1
numElementsThickness=round(sampleThickness/pointSpacings(2)); %Number of elemens in dir 2
numElementsHeight=round(sampleHeight/pointSpacings(3)); %Number of elemens in dir 3

%Define applied displacement
appliedStrain=0.3; %Linear strain (Only used to compute applied stretch)
loadingOption='compression'; % or 'tension'
switch loadingOption
    case 'compression'
        stretchLoad=1-appliedStrain; %The applied stretch for uniaxial loading
    case 'tension'
        stretchLoad=1+appliedStrain; %The applied stretch for uniaxial loading
end
displacementMagnitude=(stretchLoad*sampleHeight)-sampleHeight; %The displacement magnitude

%Material parameter set
E_youngs=1e-3;
v_poisson=0.4;

Creating model geometry and mesh

A box is created with tri-linear hexahedral (hex8) elements using the hexMeshBox function. The function offers the boundary faces with seperate labels for the top, bottom, left, right, front, and back sides. As such these can be used to define boundary conditions on the exterior.

% Create a box with hexahedral elements
cubeDimensions=[sampleWidth sampleThickness sampleHeight]; %Dimensions
cubeElementNumbers=[numElementsWidth numElementsThickness numElementsHeight]; %Number of elements
outputStructType=2; %A structure compatible with mesh view
[meshStruct]=hexMeshBox(cubeDimensions,cubeElementNumbers,outputStructType);

%Access elements, nodes, and faces from the structure
E=meshStruct.elements; %The elements
V=meshStruct.nodes; %The nodes (vertices)
Fb=meshStruct.facesBoundary; %The boundary faces
Cb=meshStruct.boundaryMarker; %The "colors" or labels for the boundary faces
elementMaterialIndices=ones(size(E,1),1); %Element material indices

Plotting model boundary surfaces and a cut view

hFig=cFigure;

subplot(1,2,1); hold on;
title('Model boundary surfaces and labels','FontSize',fontSize);
gpatch(Fb,V,Cb,'k',faceAlpha1);
colormap(gjet(6)); icolorbar;
axisGeom(gca,fontSize);

hs=subplot(1,2,2); hold on;
title('Cut view of solid mesh','FontSize',fontSize);
optionStruct.hFig=[hFig hs];
meshView(meshStruct,optionStruct);
axisGeom(gca,fontSize);

drawnow;

Defining the boundary conditions

The visualization of the model boundary shows colors for each side of the cube. These labels can be used to define boundary conditions.

%Define supported node sets
logicFace=Cb==1; %Logic for current face set
Fr=Fb(logicFace,:); %The current face set
bcSupportList_X=unique(Fr(:)); %Node set part of selected face

logicFace=Cb==3; %Logic for current face set
Fr=Fb(logicFace,:); %The current face set
bcSupportList_Y=unique(Fr(:)); %Node set part of selected face

logicFace=Cb==5; %Logic for current face set
Fr=Fb(logicFace,:); %The current face set
bcSupportList_Z=unique(Fr(:)); %Node set part of selected face

%Prescribed displacement nodes
logicPrescribe=Cb==6; %Logic for current face set
Fr=Fb(logicPrescribe,:); %The current face set
bcPrescribeList=unique(Fr(:)); %Node set part of selected face

Visualizing boundary conditions. Markers plotted on the semi-transparent model denote the nodes in the various boundary condition lists.

hf=cFigure;
title('Boundary conditions','FontSize',fontSize);
xlabel('X','FontSize',fontSize); ylabel('Y','FontSize',fontSize); zlabel('Z','FontSize',fontSize);
hold on;

gpatch(Fb,V,'kw','k',0.5);

hl(1)=plotV(V(bcSupportList_X,:),'r.','MarkerSize',markerSize);
hl(2)=plotV(V(bcSupportList_Y,:),'g+','MarkerSize',markerSize*2);
hl(3)=plotV(V(bcSupportList_Z,:),'b*','MarkerSize',markerSize);
hl(4)=plotV(V(bcPrescribeList,:),'ko','MarkerSize',markerSize);

legend(hl,{'BC x support','BC y support','BC z support','BC z prescribe'});

axisGeom(gca,fontSize);
camlight headlight;
drawnow;

Defining the abaqus input structure

See also abaqusStructTemplate and abaqusStruct2inp and the abaqus user manual.

%%--> Heading
abaqus_spec.Heading.COMMENT{1}='Job name: ABAQUS inp file creation demo';
abaqus_spec.Heading.COMMENT{2}='Generated by: GIBBON';

%%--> Preprint
abaqus_spec.Preprint.ATTR.echo='NO';
abaqus_spec.Preprint.ATTR.model='NO';
abaqus_spec.Preprint.ATTR.history='NO';
abaqus_spec.Preprint.ATTR.contact='NO';

%--> Part

% Node
nodeIds=(1:1:size(V,1))';
abaqus_spec.Part.COMMENT='This section defines the part geometry in terms of nodes and elements';
abaqus_spec.Part.ATTR.name='Cube';
abaqus_spec.Part.Node={nodeIds,V};

% Element
elementIds=(1:1:size(E,1));
abaqus_spec.Part.Element{1}.ATTR.type='C3D8';%'C3D8R';
abaqus_spec.Part.Element{1}.VAL={elementIds(:),E};

% Element sets
abaqus_spec.Part.Elset{1}.ATTR.elset='Set-1';
abaqus_spec.Part.Elset{1}.VAL=elementIds;

% Sections
abaqus_spec.Part.Solid_section.ATTR.elset='Set-1';
abaqus_spec.Part.Solid_section.ATTR.material='Elastic';

%%--> Assembly
abaqus_spec.Assembly.ATTR.name='Assembly-1';
abaqus_spec.Assembly.Instance.ATTR.name='Cube-assembly';
abaqus_spec.Assembly.Instance.ATTR.part='Cube';

abaqus_spec.Assembly.Nset{1}.ATTR.nset='Set-1';
abaqus_spec.Assembly.Nset{1}.ATTR.instance='Cube-assembly';
abaqus_spec.Assembly.Nset{1}.VAL=bcSupportList_X(:)';

abaqus_spec.Assembly.Nset{2}.ATTR.nset='Set-2';
abaqus_spec.Assembly.Nset{2}.ATTR.instance='Cube-assembly';
abaqus_spec.Assembly.Nset{2}.VAL=bcSupportList_Y(:)';

abaqus_spec.Assembly.Nset{3}.ATTR.nset='Set-3';
abaqus_spec.Assembly.Nset{3}.ATTR.instance='Cube-assembly';
abaqus_spec.Assembly.Nset{3}.VAL=bcSupportList_Z(:)';

abaqus_spec.Assembly.Nset{4}.ATTR.nset='Set-4';
abaqus_spec.Assembly.Nset{4}.ATTR.instance='Cube-assembly';
abaqus_spec.Assembly.Nset{4}.VAL=bcPrescribeList(:)';

abaqus_spec.Assembly.Nset{5}.ATTR.nset='all';
abaqus_spec.Assembly.Nset{5}.ATTR.instance='Cube-assembly';
abaqus_spec.Assembly.Nset{5}.VAL=1:1:size(V,1);

%%--> Material
abaqus_spec.Material.ATTR.name='Elastic';
abaqus_spec.Material.Elastic=[E_youngs v_poisson];

%%--> Step
abaqus_spec.Step.ATTR.name='Step-1';
abaqus_spec.Step.ATTR.nlgeom='YES';
abaqus_spec.Step.Static=[0.1 1 1e-5 0.1];

% Boundary
abaqus_spec.Step.Boundary{1}.VAL={'Set-1',[1,1]};
abaqus_spec.Step.Boundary{2}.VAL={'Set-2',[2,2]};
abaqus_spec.Step.Boundary{3}.VAL={'Set-3',[3,3]};
abaqus_spec.Step.Boundary{4}.VAL={'Set-4',[3,3],displacementMagnitude};

%Output
abaqus_spec.Step.Restart.ATTR.write='';
abaqus_spec.Step.Restart.ATTR.frequency=0;

abaqus_spec.Step.Output{1}.ATTR.field='';
abaqus_spec.Step.Output{1}.ATTR.variable='PRESELECT';
abaqus_spec.Step.Output{2}.ATTR.history='';
abaqus_spec.Step.Output{2}.ATTR.variable='PRESELECT';
abaqus_spec.Step.Node_print.ATTR.nset='all';
abaqus_spec.Step.Node_print.ATTR.frequency = 1;
abaqus_spec.Step.Node_print.VAL='COORD';
abaqus_spec.Step.El_print{1}.VAL='S';
abaqus_spec.Step.El_print{2}.VAL='E';
abaqusStruct2inp(abaqus_spec,abaqusInpFileName);

% textView(abaqusInpFileName);

Run the job using Abaqus

lockFileName=fullfile(savePath,[abaqusInpFileNamePart,'.lck']);
if exist(lockFileName,'file')
    warning('Lockfile found and deleted')
    delete(lockFileName);
end
oldPath=pwd; %Get current working directory
cd(savePath); %Set new working directory to match save patch

abaqusPath='abaqus';%'/usr/bin/abaqus'; %Abaqus excute command or path
runFlag=system([abaqusPath,' inp=',abaqusInpFileName,' job=',abaqusInpFileNamePart,' interactive ask_delete=OFF']);

cd(oldPath); %Restore working directory
Analysis initiated from SIMULIA established products
Abaqus JOB tempModel
Abaqus 3DEXPERIENCE R2018x
Abaqus License Manager checked out the following licenses:
Abaqus/Standard checked out 5 tokens from Flexnet server cert1.srv.nuigalway.ie.
<60 out of 85 licenses remain available>.
Abaqus Warning: Your Abaqus license will expire in 26 days.
Begin Analysis Input File Processor
Tue Jun  4 12:11:01 2019
Run pre
Tue Jun  4 12:11:02 2019
End Analysis Input File Processor
Begin Abaqus/Standard Analysis
Tue Jun  4 12:11:02 2019
Run standard
Tue Jun  4 12:39:07 2019
Abaqus Error: The executable standard
aborted with system error "Termination signal" (signal 9).
Please check the .dat, .msg, and .sta files for error messages if the files
exist.  If there are no error messages and you cannot resolve the problem,
please run the command "abaqus job=support information=support" to report and
save your system information.  Use the same command to run Abaqus that you
used when the problem occurred.  Please contact your local Abaqus support
office and send them the input file, the file support.log which you just
created, the executable name, and the error code.
Begin Convert MFS to SFS
Tue Jun  4 12:39:07 2019
Run SMASimUtility
Tue Jun  4 12:39:07 2019
End Convert MFS to SFS
Abaqus/Analysis exited with errors

Import and visualize abaqus results

Importing the abaqus .dat file

[abaqusData]=importAbaqusDat(abaqusDATFileName);

Get element data

E_effectiveStress=zeros(size(E,1),numel(abaqusData.STEP.INCREMENT)+1);
E_effectiveStrain=zeros(size(E,1),numel(abaqusData.STEP.INCREMENT)+1);
for q=1:1:numel(abaqusData.STEP.INCREMENT)

    for d=1:1:2
        dataSet=abaqusData.STEP.INCREMENT(q).elementOutput(d); %Get data structure
        switch d
            case 1
                % Get element data across all 8 integration points
                D11_PT=reshape(dataSet.data.S11,8,size(E,1))';
                D22_PT=reshape(dataSet.data.S22,8,size(E,1))';
                D33_PT=reshape(dataSet.data.S33,8,size(E,1))';
                D12_PT=reshape(dataSet.data.S12,8,size(E,1))';
                D13_PT=reshape(dataSet.data.S13,8,size(E,1))';
                D23_PT=reshape(dataSet.data.S23,8,size(E,1))';
            case 2
                % Get element data across all 8 integration points
                D11_PT=reshape(dataSet.data.E11,8,size(E,1))';
                D22_PT=reshape(dataSet.data.E22,8,size(E,1))';
                D33_PT=reshape(dataSet.data.E33,8,size(E,1))';
                D12_PT=reshape(dataSet.data.E12,8,size(E,1))';
                D13_PT=reshape(dataSet.data.E13,8,size(E,1))';
                D23_PT=reshape(dataSet.data.E23,8,size(E,1))';
        end

        % Get mean element metrics
        D11=mean(D11_PT,2);
        D22=mean(D22_PT,2);
        D33=mean(D33_PT,2);
        D12=mean(D12_PT,2);
        D13=mean(D13_PT,2);
        D23=mean(D23_PT,2);

        % Calculate effective (Von Mises) metrics
        switch d
            case 1
                E_effectiveStress(:,q+1)=(1/sqrt(2)).*sqrt((D11-D22).^2+(D11-D33).^2+(D33-D11).^2+6*D12.^2+6*D23.^2+6*D13.^2);
            case 2
                E_effectiveStrain(:,q+1)=(1/sqrt(2)).*sqrt((D11-D22).^2+(D11-D33).^2+(D33-D11).^2+6*D12.^2+6*D23.^2+6*D13.^2);
        end
    end
end

% diff(E_effectiveStress,1,2)./diff(E_effectiveStrain,1,2)

Plotting the simulated results using anim8 to visualize and animate deformations

%Getting final nodal coordinates
V_def=[abaqusData.STEP(1).INCREMENT(end).nodeOutput.data.COOR1...
    abaqusData.STEP(1).INCREMENT(end).nodeOutput.data.COOR2...
    abaqusData.STEP(1).INCREMENT(end).nodeOutput.data.COOR3];
U=V_def-V; %Displacements

colorDataVertices=sqrt(sum(U.^2,2)); %Displacement magnitude data for coloring

timeVec=[0 abaqusData.STEP(1).INCREMENT(:).TOTAL_TIME_COMPLETED];

% Get limits for plotting
minV=min([V;V_def],[],1); %Minima
maxV=max([V;V_def],[],1); %Maxima

% Create basic view and store graphics handle to initiate animation
hf=cFigure; %Open figure
gtitle([abaqusInpFileNamePart,': Displacement data. Press play to animate']);
hp=gpatch(Fb,V_def,colorDataVertices,'k',1); %Add graphics object to animate
gpatch(Fb,V,0.5*ones(1,3),'k',0.25); %A static graphics object
axisGeom(gca,fontSize);
colormap(gjet(250)); colorbar;
caxis([0 max(colorDataVertices)]);
axis([minV(1) maxV(1) minV(2) maxV(2) minV(3) maxV(3)]); %Set axis limits statically
view(130,25); %Set view direction
camlight headlight;

% Set up animation features
animStruct.Time=timeVec; %The time vector
for qt=1:1:numel(timeVec) %Loop over time increments
    if qt>1
        V_def=[abaqusData.STEP(1).INCREMENT(qt-1).nodeOutput.data.COOR1...
            abaqusData.STEP(1).INCREMENT(qt-1).nodeOutput.data.COOR2...
            abaqusData.STEP(1).INCREMENT(qt-1).nodeOutput.data.COOR3];
    else
        V_def=V;
    end
    U=V_def-V; %Displacements
    colorDataVertices=sqrt(sum(U(:,3).^2,2)); %New color data

    %Set entries in animation structure
    animStruct.Handles{qt}=[hp hp]; %Handles of objects to animate
    animStruct.Props{qt}={'Vertices','CData'}; %Properties of objects to animate
    animStruct.Set{qt}={V_def,colorDataVertices}; %Property values for to set in order to animate
end
anim8(hf,animStruct); %Initiate animation feature
drawnow;

Plotting the simulated results using anim8 to visualize and animate deformations

%Getting final nodal coordinates
V_def=[abaqusData.STEP(1).INCREMENT(end).nodeOutput.data.COOR1...
    abaqusData.STEP(1).INCREMENT(end).nodeOutput.data.COOR2...
    abaqusData.STEP(1).INCREMENT(end).nodeOutput.data.COOR3];
U=V_def-V; %Displacements

[FE,C_FE_effectiveStress]=element2patch(E,E_effectiveStress(:,end),'hex8');
[indBoundary]=tesBoundary(FE,V);
FEb=FE(indBoundary,:);
colorDataFaces=C_FE_effectiveStress(indBoundary);

timeVec=[0 abaqusData.STEP(1).INCREMENT(:).TOTAL_TIME_COMPLETED];

% Get limits for plotting
minV=min([V;V_def],[],1); %Minima
maxV=max([V;V_def],[],1); %Maxima

% Create basic view and store graphics handle to initiate animation
hf=cFigure; %Open figure
gtitle([abaqusInpFileNamePart,': Effective stress data. Press play to animate']);
hp=gpatch(FEb,V_def,colorDataFaces,'k',1); %Add graphics object to animate
gpatch(FEb,V,0.5*ones(1,3),'k',0.25); %A static graphics object
axisGeom(gca,fontSize);
colormap(gjet(250)); colorbar;
caxis([0 max(E_effectiveStress(:))]);
axis([minV(1) maxV(1) minV(2) maxV(2) minV(3) maxV(3)]); %Set axis limits statically
view(130,25); %Set view direction
camlight headlight;

% Set up animation features
animStruct.Time=timeVec; %The time vector
for qt=1:1:numel(timeVec) %Loop over time increments
    if qt>1
        V_def=[abaqusData.STEP(1).INCREMENT(qt-1).nodeOutput.data.COOR1...
            abaqusData.STEP(1).INCREMENT(qt-1).nodeOutput.data.COOR2...
            abaqusData.STEP(1).INCREMENT(qt-1).nodeOutput.data.COOR3];
    else
        V_def=V;
    end
    U=V_def-V; %Displacements

    [~,C_FE_effectiveStress]=element2patch(E,E_effectiveStress(:,qt),'hex8');
    colorDataFaces=C_FE_effectiveStress(indBoundary); %New color data

    %Set entries in animation structure
    animStruct.Handles{qt}=[hp hp]; %Handles of objects to animate
    animStruct.Props{qt}={'Vertices','CData'}; %Properties of objects to animate
    animStruct.Set{qt}={V_def,colorDataFaces}; %Property values for to set in order to animate
end
anim8(hf,animStruct); %Initiate animation feature
drawnow;

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) 2018 Kevin Mattheus Moerman

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/.

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) 2019 Kevin Mattheus Moerman

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/.