XML Input Files for NairnFEA

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Input XML files for NairnFEA must conform to the definition on this page.

FEA Input XML File Definition

All XML input command files for FEA calculationsin NairnFEA must conform to the following document definition including order of all XML elements. This template lists only the top-level main element and their next-level subordinate elements. For the subordinate elements, those separated by a vertical bar (|) mean any one of those elements in any order while those separated by commas mean in exactly that order. A more formal definition for FEA input XMlL files is given in the DTD file provided in the source code files at NairnFEA/input/NairnFEA.dtd.

<?xml version='1.0'?>
  <!ENTITY force "100">
XML declaration1,2
<JANFEAInput version='3'>
Top level element3
    ( Analysis | Description | Output
               | Select | DevelFlag )

One Analysis is required.
    ( Keypoints, Path, Area )
    ( NodeList, ElementList)

The mesh can be generated (with keypoints, paths and areas) or explicit, but not both
These blocks used when creating a mesh with images and shapes
    ( property commands )
  </Material >

Define each material in a separate Material block
    ( Cracktip )
    ( DisplacementBCs | LoadBCs | EdgeBCs 
                      | BCLine | BCPt | Periodic )
    ( Resequence )

Define all boundary conditions4
    ( Temperature, StressFreeTemp)


Sample Input XML File

Click this link to see a sample XML FEA input command file for analysis of an end-loaded cantilever beam.


  1. The !DOCTYPE element defines the file type and has the SYSTEM option to provide a path to a Document Type Definition (or DTD) file. The path is needed when you run the code with the validation option (-v), which is highly recommended. The required DTD file for FEA calculations is provided in the /input folder of the source code files.
  2. The !DOCTYPE element can define any number of entities. These entities can be used elsewhere in the text of the XML file and they will be replaced by the text in the entity definition. Entities can define values that make it easier to read input XML files and easier to modify them for new calculations.
  3. All input commands are in the top-level <JANFEAInput> element. The version attribute is option, but might be used in the future.
  4. if the optional CrackTip and Resequence commands are used, they must be first and last, respectively, in the GridBCs element. The rest of the subordinate commands can be in any order.