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===== Unv2oofem convertor =====
The unv2oofem convertor translates SRDC's I-DEAS (Integrated Design and Engineering Analysis Software) unv-mesh file format to native OOFEM input file. Unv file-type is an open ASCII datafile, which is used by several finite element codes. The CAD/mesh generating open-source software [[http://www.salome-platform.org/|SALOME]] is intended to create such unv files. Unv2oofem convertor handles
  * mesh geometry
  * material assignment
  * assignment of boundary conditions and conditions in nodes 

===== How to obtain the unv2oofem =====
The unv2oofem is a part of the [[http://www.oofem.org/en/miscellaneous/svn.html|svn OOFEM distribution]], which is also [[http://www.oofem.org/svn/trunk/tools/unv2oofem|downloadable by files]]. It is possible, but obsolete due to simultaneous updates, to {{:unv2oofem:unv2oofem.zip |download}} older release unv2oofem 1.0. The unv2oofem convertor consists from three files:
  * [[http://www.oofem.org/svn/trunk/tools/unv2oofem/unv2oofem.py|unv2oofem.py]] - python script reading unv input files and creating OOFEM input file
  * [[http://www.oofem.org/svn/trunk/tools/unv2oofem/oofemctrlreader.py|oofemctrlreader.py]] - general manipulation classes related to OOFEM data format.
  * [[http://www.oofem.org/svn/trunk/tools/unv2oofem/unv2x.py|unv2x.py]] - the base class written by [[http://www.caelinux.com|J.Cugnoni]]. This file creates an internal FEM object structure in memory.

===== How to use the unv2oofem =====
The unv2oofem operates on two files
  * **unv file** - defines topology (elements, nodes, edges, faces). Each entity transporting to OOFEM must be included in a group, which is also defined with unv file. For example in Salome can be the groups easily defined by clicking to the icon "create group" in the menu bar.
  * **control file** - describes mapping of unv groups to OOFEM entities. These include material description, loads, supports, type of problem (solid mechanics, transports), solver parameters, outputs etc. The mapping relies on an element ID in unv-file, which shows the following table. Each ID can be mapped to corresponding OOFEM olement, e.g. ID 11 can represent Truss1D or Beam3D OOFEM elements.

^ Element type      ^ Unv number ^ OOFEM's finite elements (not all are mapped in the convertor) ^
|Truss, beam, edge: 2 nodes, linear | 11| Truss1D, Truss2D, Truss3D, Beam2D, Beam3D |
|Truss, beam, edge: 3 nodes, quadratic | 22| Interface2DQuad |
|Triangle: 3 nodes, linear | 41| TrPlaneStress2D, TrPlaneStrRot, TrplaneStrain,  CCTPlate, CCTPlate3d,  RerShell,  Tr_shell01, Axisymm3D, Interface3DTrlin,  Tr1HT, TrAxisym1HT, Tr1CBS, Tr1SUPG, Tr1SUPGAxi |
|Triangle: 6 nodes, quadratic | 42| QTrPlStr, Tr21SUPG  |
|Quad: 4 nodes, linear | 44| Planestress2D, Quad1PlaneStrain, L4axisymm, Quad1HT,  Quad1HMT, QuadAxisym1HT  |
|Quad: 8 nodes, quadratic | 45| QPlanestress2D, Q4Axisymm |
|Tetrahedron: 4 nodes, linear|111| LTRSpace, Tetrah1ht, PY1 3D SUPG |
|Brick: 8 node, linear|115| LSpace, LSpaceBB, Brick1HT,  Brick1HMT  |
|Brick: 20 nodes, quadratic|116| QSpace, QBrick1ht, QBrick1hmt |
|Tetrahedron: 10 nodes, quadratic|118|


===== Minimal working example =====
The minimal working example simulates a plane-stress problem. The geometry is meshed using linear quadrilateral finite elements. Two materials are included, one edge is supported and the opposite edge is loaded by tractions.

{{:unv2oofem:scheme.png?400|Set-up of the example.}}

==== Creating unv file in Salome ====
This section demonstrates how to create the mesh in Salome and how to build the necessary groups:
  - The geometry is created in the //Geometry module// as a rectangle. Then go to //Mesh module// and hit //Mesh->Create mesh//. In the dialog, select the rectangle as a Geometry, assign 1D algorithm (Wire discretization) and 1D hypothesis (Maximal size), assign 2D algorithm (Quadrangle mapping). Select //Mesh_1// in the left panel and by right-clicking invoke //Compute//.\\ {{:unv2oofem:create_mesh.png?400|Create mesh}}
  - At this moment, finite elements are created. The resulting mesh is shown on the screen with the //mesh info// label.\\ {{:unv2oofem:mesh_computation.png?400|Mesh info}} {{:unv2oofem:mesh.png?400|Mesh}}
  - Click //Mesh->Create group//, choose face and select finite elements of the first material group with the help of Shift key. Two groups //material_1// and //material_2// of finite elements are created, on which material properties will be mapped.\\ {{:unv2oofem:create_group_mat1.png?400|Create group 1st material}} {{:unv2oofem:create_group_mat2.png?400|Create group 2nd material}}\\ Both materials can be colored.\\ {{:unv2oofem:mesh_materials.png?400|Colored groups of materials}}
  - Define groups for supports and loads in the same way, by selecting appropriate edges and nodes. Create two groups //support_nodes// and //load_edge//.\\ {{:unv2oofem:support.png?400|}}{{:unv2oofem:load.png?400|}}\\ {{:unv2oofem:create_group_support.png?400|}}{{:unv2oofem:create_group_load.png?400|}}
  - The unv file is exported using //File/Export// while the mesh is selected. The Salome native file //hdf//, unv output file and control file is {{:unv2oofem:exam.zip|downloadable as a zip file}}.
 
==== Creating control file ====
We need to define information about materials, tractions and boundary conditions. {{:unv2oofem:exam.zip|The control file}} looks like 
<code text>
exam.out
This example shows how to convert unv file to OOFEM input file.
linearstatic nsteps 1 nmodules 1
vtkxml tstep_all domain_all primvars 1 1 vars 2 4 1 stype 1
domain 2dplanestress
OutputManager tstep_all dofman_all element_all
ncrosssect 1 nmat 2 nbc 2 nic 0 nltf 1
SimpleCS 1 thick 1.0 width 1.0
isole 1 d 0.0 e 15.0 n 0.25 tAlpha 0.0
isole 2 d 0.0 e 20.0 n 0.25 tAlpha 0.0
BoundaryCondition 1 loadTimeFunction 1 prescribedvalue 0.0
ConstantEdgeLoad 2 loadTimeFunction 1 Components 2 10.0 0.0 loadType 3 ndofs 2
ConstantFunction 1 f(t) 1.0
#Comment may be inserted anywhere
#Data for extractor, if necessary
#%BEGIN_CHECK% tolerance 1.e-8
## check reactions
#REACTION tStep 1 number 1 dof 1
#NODE tStep 1 number 5 dof 1 unknown d
#%END_CHECK%

group load_edge
elemprop bLoadNum 2
etype[11]

group support_nodes
nodeprop bc 2 1 1

group material_1
elemprop mat 1 crosssect 1
etype[44] PlaneStress2d

group material_2
elemprop mat 2 crosssect 1
etype[44] PlaneStress2d
</code>
  
==== Run the unv2oofem ====
The unv2oofem convertor creates the OOFEM input file exam.in executing a python command:

$ unv2oofem.py  exam.unv  exam.ctrl  exam.in
 
All the files can be {{:unv2oofem:exam.zip|downloaded as a ZIP file}}.