Difference between revisions of "FEA Mesh Generation Commands"
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== Scripted Input Files == | == Scripted Input Files == | ||
In scripted input files, you build the mesh by using multiple [[# | In scripted input files, you build the mesh by using multiple [[#mesh_cmds|mesh generation commands]]. These commands are usually grouped together, but may be at various locations in the input file. For example, a simple 2D, rectangular mesh of width <tt>#length</tt>, height <tt>#height</tt>, and thickness <tt>#thick</tt> with <tt>#horiz</tt> elements in the horizontal direction and <tt>#vert</tt> elements in the vertical direction (where terms beginning in number signs are [[Variable Names|script variables]]) can be created with: | ||
Area #matname$,#thick | Area #matname$,#thick | ||
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Resequence "BotRight" | Resequence "BotRight" | ||
= | <span id="mesh_cmds"></span>The following commands are used for generating the mesh in scripted files. | ||
The | |||
* [[Area Command|Area]]: Define an area for mesh generation. | * [[Area Command|Area]]: Define an area for mesh generation. | ||
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* [[Keypoint Command|Keypoint]]: Define a keypoint used in defining [[Path Command|paths]] | * [[Keypoint Command|Keypoint]]: Define a keypoint used in defining [[Path Command|paths]] | ||
* [[Keypoint Command|Keypoints]]: Add multiple defined keypoints to a [[Path Command|path]]. | * [[Keypoint Command|Keypoints]]: Add multiple defined keypoints to a [[Path Command|path]]. | ||
* [[Resequence Command]]: To turn on the option to resequence the nodes, which will minimize the bandwidth of the problem and speed the calculations. | * [[Resequence Command]]: To turn on the option to resequence the nodes, which will minimize the bandwidth of the problem and speed the calculations. | ||
Revision as of 10:32, 3 January 2014
The best way to generate an FEA mesh is to use Keypoint, Path, and Area commands.
Scripted Input Files
In scripted input files, you build the mesh by using multiple mesh generation commands. These commands are usually grouped together, but may be at various locations in the input file. For example, a simple 2D, rectangular mesh of width #length, height #height, and thickness #thick with #horiz elements in the horizontal direction and #vert elements in the vertical direction (where terms beginning in number signs are script variables) can be created with:
Area #matname$,#thick
Path "Bottom",#horiz
Keypoint "BotLeft",0,0
Keypoint "BotRight",#length,0
EndPath
Path "Right",#vert
Keypoints "BotRight"
Keypoint "TopRight",#length,#height
EndPath
Path "Top",#horiz
Keypoints "TopRight"
Keypoint "TopLeft",0,#height
EndPath
Path "Left",#vert
Keypoints "TopLeft","BotRight"
EndPath
EndArea
Resequence "BotRight"
The following commands are used for generating the mesh in scripted files.
- Area: Define an area for mesh generation.
- Path: Define a path used in defining areas.
- Paths: Add multiple defined paths to an area.
- Keypoint: Define a keypoint used in defining paths
- Keypoints: Add multiple defined keypoints to a path.
- Resequence Command: To turn on the option to resequence the nodes, which will minimize the bandwidth of the problem and speed the calculations.
XML Input Files
In XML input files, you build the mesh with mesh generation commands that must be within a single <Mesh> block. Here is a <Mesh> block that creates at 50X10 mm rectangular mesh with 6 elements in the horizontal direction and 3 in the vertical direction:
<Mesh>
<Keypoints>
<pt x='0' y='0' id='lowerleft'/>
<pt x='0' y='10' id='upperleft'/>
<pt x='50' y='0' id='lowerright'/>
<pt x='50' y='10' id='upperright'/>
</Keypoints>
<Path id="bottom" intervals='6' ratio='1'>
<keypt id='lowerleft'/>
<keypt id='lowerright'/>
</Path>
<Path id="right" intervals='3'>
<keypt id='lowerright'/>
<keypt id='upperright'/>
</Path>
<Path id="top" intervals='6'>
<keypt id='upperright'/>
<keypt id='upperleft'/>
</Path>
<Path id="left" intervals='3'>
<keypt id='upperleft'/>
<keypt id='lowerleft'/>
</Path>
<Area mat="1" thick="10" type="4" flip="0" angle="0">
<path id="bottom"/>
<path id="right"/>
<path id="top"/>
<path id="left"/>
</Area>
</Mesh>
Mesh Generation Commands
The fundamental XML commands for generating a mesh are:
- <Area>: Define an area for mesh generation.
- <Path>: Define a path used in defining areas.
- <Keypoints>: Define a key point used in defining paths
Using Images and Shapes
If some elements in the generated mesh are set the material id _NONE_ (see Area Command) or mat = 0 (see <Area> Command), you can follow mesh creation with image and shape commands to fill in material types, angles, and define the final mesh geometry. This option is described here.