Creating FNF Files for External Loads and Constraints

Creo Simulate > Modeling Structure and Thermal Problems > Thermal Boundary Conditions > Convection Conditions > Using External Data > 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.

FNF files are backward-compatible.

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:

Instruction Names	Abbreviation	Section Name
STATISTICS	STT	HEADER
ELEM_TYPE	ETP	ELEM_TYPE
NODE	ND	MESH
ELEM	EL	MESH
CON_CASE	CC	LOADS
LOAD_TYPE	LTP	LOADS
LOAD	LD	LOADS

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.