Creating FNF Files for External Loads and Constraints
FEM Neutral Format (FNF) files, with the extension fnf, are organized into sections. When you are creating an FNF file that will be used to import an external load or constraint, you need only five of these sections.
Each section describes its own class of objects. The order of sections in the FNF file is critical, since information from the earlier defined sections may be required in subsequent sections.
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FNF files are backward-compatible.
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Create the following sections in an FNF file to import an external load or constraint:
• HEADER—general information about the file and the model. This section can contain the following instructions:
◦ TITLE—describes the name of your model
◦ STATISTICS—provides information about the number of element types, coordinate systems, materials, element properties, nodes, and elements in your model
• ELEM_TYPES—definition of element types
• MESH—definition of the model's nodes and elements
• LOADS—description of applied constraint cases, loads, and boundary conditions
The following table lists instructions required for importing external loads and constraints, their standard abbreviations, and the sections in which they may appear:
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Instruction Names
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Abbreviation
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Section Name
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|---|---|---|
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STATISTICS
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STT
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HEADER
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ELEM_TYPE
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ETP
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ELEM_TYPE
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NODE
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ND
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MESH
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ELEM
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EL
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MESH
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CON_CASE
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CC
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LOADS
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LOAD_TYPE
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LTP
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LOADS
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LOAD
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LD
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LOADS
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Each section must start with the following text string:
%START_SECT : SECTION_NAME
Each section must end with the following text string:
%END_SECT
For more information about FNF files, see FEM Neutral Format File.