PATRAN Interface

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The interface writes coordinate, connectivity, boundary condition and property information in the PATRAN neutral file format (version 2.5). The following PATRAN packets are supported by this interface:

Creating the PATRAN Input File

The translator writes the PATRAN Neutral File using the following files: To create the PATRAN input file, select the following menu entries from the ICEM CFD/CAE manager: Options for the PATRAN interface:

Defining boundary conditions for PATRAN (optional)

The following sections gives an overview of the boundary conditions and properties supported by the PATRAN interface as well as how to define them.

Element Property ID (in Packet 02):

Select a surface family for a 2D model or a volume family for a 3D model. Then select "Element PID" from the BC menu and enter the PID number (integer).

Repeat the above procedure for all surface families (in 2D) or volume families (in 3D) for which you need to define a property ID number. If no PID number is defined for an element, it gets the default value of zero unless the interface is ran using the option "Automatic creation of regions". The element PID numbers are written in packet 2 (Element Data) of the PATRAN neutral file.

Material Properties (Packet 03):

Material properties must be defined on volumes for 3D models or on surfaces for 2D models.  The user has 3 material type options:

After selecting the type of material to define, a window opens with a list of fields to fill for the chosen material type.

Element Properties (Packet 04):

The element properties must be defined on volumes for 3D models or on surfaces for 2D models.  It allows the user
to set the configuration ID and up to 38 property data. Each one of these can be either a character string or numerical value.
 

Coordinate Frames (Packet 05):

Coordinate frames are defined in the mesh generator. When the translator is ran, the coordinate frames are automatically written in the file "wpatran.par" which is read by the translator and used to create Packet05.

Distributed Loads (Packet 06):

The distributed loads can be defined on the boundaries i.e. on edges for a 2D model or on surfaces for a 3D model. After selecting an edge or surface family, click on "Distributed Loads" in the BC menu. You will then be prompt to enter the following:

This procedure is repeated for all entities where distributed load (pressure, shear, etc...) need to be defined. It is assumed that these loads are applied at the boundary of the model; loads assigned on blocks' interfaces are ignored by the translator.

The three components of the load follow the parametric axis I, J and K. A positive load component is oriented toward the increasing direction of the parametric axis and a negative component toward the decreasing direction. The parametric directions I, J, K can be displayed in the mesher, and reoriented if needed, prior to defining the loads. Special attention must be paid in 2D to ensure that all subfaces' normals are oriented toward the positive K-direction.

For a normal load, components are computed by the translator in order to insure that the orientation corresponds to a normal load. A positive load is applied outward (suction) while a negative one is applied inward (pressure).

The non-zero load components are written in packet 6 (Distributed Loads) of the PATRAN neutral file where they are linked to the elements' faces and nodes.

Node Forces (Packet 07):

The node forces can be defined on edges for a 2D model and on surfaces or edges for a 3D model. Only one node force per node is written in the Patran Neutral file. In cases where several node forces are applied to the same node, the load with the highest load set ID number is chosen to overwrite the others.

After selecting an edge or surface, click on "Node Forces" in the BC menu. You will then be prompt to enter the following:

When the type is set to normal, the translator computes the normal vector at each node of the surface or edge where the load is applied, and determines for each node the 3 load components which insure that the resulting force vector is normal to the boundary. A positive force is applied outward (suction) while a negative one is applied inward (pressure).

The non-zero load components are written in packet 07 of the PATRAN neutral file where they are linked to the node numbers.

Node Displacements (Packet 08):

The node displacements can be defined on edges for a 2D model and on surfaces or edges for a 3D model. p>After selecting an edge or surface, click on "Node Displacements" in the BC menu. You will then be prompt to enter the following:

The degree of freedom label indicates which displacement components should be set. The valid degree of freedom labels are:

                        
        UX, UY, UZ              Translation in X, Y, Z
        ROTX, ROTY, ROTZ        Rotation about X, Y, Z
        ALLTR                   All translations
        ALLRO                   All rotations
        ALL                     All degrees of freedom
Node displacements can also be defined normal to the boundaries. In such case, the translator computes a local coordinate system normal to the boundary at each node of the surface or edge where the displacement is applied. The normal displacement vector is expressed in the local coordinate system. A positive normal displacement is applied outward (suction) while a negative one is applied inward (pressure).

The node displacements are written in packet 8 of the PATRAN neutral file.

Node Temperatures (Packet 10):

In 2D, node temperatures can be defined on subfaces and edges, and in 3D, on domains, subfaces and edges. Select an entity then the BC menu option "Node Temperatures". You will then be prompt to enter:

Repeat the above procedure for all entities where you need to define the nodal temperature. Note that node temperatures defined on subfaces overwrite those defined on domains, node temperatures defined on edges overwrite those defined on subfaces (when they share common nodes). The node temperatures are written in packet 10 of the PATRAN neutral file.

Nodal Heat Source (Packet 15):

In 2D, nodal heat flux can be defined on faces and on edges, and in 3D, on domains, subfaces and edges. Select an entity then the BC menu option "Nodal Heat Source". You will then be prompt to enter:

Repeat the above procedure for all entities where you need to define the nodal heat flux. Note that nodal heat flux defined on subfaces overwrite those defined on domains and nodal heat flux defined on edges overwrite those defined on subfaces (when they share common nodes). The nodal heat flux are written in packet 15 of the PATRAN neutral file.

Distributed Heat Source (Packet 16):

In 2D, distributed heat flux can be defined only on edges, and in 3D, only on subfaces. Select an entity then the BC menu option "Distributed Heat Source". You will then be prompt to enter:

Repeat the above procedure for all entities where you need to define a distributed heat flux. The distributed heat flux are written in packet 16 of the PATRAN neutral file.

Convection Coefficients (Packet 17):

In 2D, the convection coefficients can be defined only on edges, and in 3D, only on subfaces. Select an entity then the BC menu option "Convection Coefficients". You will then be prompt to enter:

Repeat the above procedure for all entities where you need to define a convection coefficient. The convection coefficient are written in packet 17 of the PATRAN neutral file.

Radiation Emissivity Values (Packet 18):

In 2D, the radiation emissivity values can be defined only on edges, and in 3D, only on subfaces. Select an entity then the BC menu option "Radiation Emissivity Values". You will then be prompt to enter:

Repeat the above procedure for all entities where you need to define a radiation emissivity value. The convection coefficient are written in packet 18 of the PATRAN neutral file.

Named Component Definition (Packet 21):

In 2D, names can be defined on subfaces and edges, and in 3D, on domains, subfaces and edges. Select an entity then the BC menu option "Named Component Definition". You will then be prompt to enter the component name.

A component number is assigned to each component name within the translator. The named components are linked to the node numbers in packet 21.

When running the translator, an additional option is available to create automatically a named component for each topological entity. If this option is selected, a component is generated for each family, domain or subface (depending on the origin of the grid).

Available element types

The type of elements supported by the ICEM-PATRAN translator are:
 
        in 1D    - 2 or 3 points line
        in 2D    - 3 or 6 points triangle
                 - 4, 8 or 9 points quadrilateral
        in 3D    - 4 or 10 points tetrahedral
                 - 8, 20 or 27 points hexahedral
                 - 6, 15 or 18 points wedge pentahedral
                 - 5 or 14 points pyramidal pentahedral

Content of the PATRAN Neutral File created with the PATRAN translator

This section describes for each PATRAN packet supported by the translator which variables are used and what they mean.

Packet 25: Title Card

The title card packet contains the following:
        25 ID IV KC
        TITLE

where:  ID = 0 (not applicable)
        IV = 0 (not applicable
        KC = 1
        TITLE = ICEM-PATRAN INTERFACE - Version ... -
Packet 26: Summary Data
The summary data packet contains the following:
        26 ID IV KC N1 N2 N3 N4 N5
        DATE TIME VERSION

where:  ID = 0 (not applicable)
        IV = 0 (not applicable)
        KC = 1
        N1 = number of nodes
        N2 = number of elements
        N3 = number of materials
        N4 = number of element properties
        N5 = number of coordinate frames
        DATE = dd-mm-yy
        TIME = hh:mm:ss
        VERSION = 2.5
Packet 01: Node Data
The node data packet contains the following:
        1 ID IV KC
        X Y Z 
        ICF GTYPE NDF CONFIG CID PSP

where:  ID = node ID
        IV = 0 (not applicable)
        KC = number of lines in data card = 2
        X, Y, Z = X, Y, Z cartesian coordinate of the node
        ICF = 1 (referenced)
        GTYPE = G
        NDF = 2 or 3 for 2D or 3D model respectively
        CONFIG = 0 (not applicable)
        CID = 0 i.e. global cartesian coordinate system
        PSPC = 000000 (not used)
Packet 02: Element Data
The element data packet contains the following:
        2 ID IV KC N1 N2
        NODES CONFIG PID CEID q1 q2 q3
        LNODES
        ADATA

where:  ID = element ID
        IV = shape (2=bar, 3=tri, 4=quad, 5=tet, 7=wedge, 8=hex, 9=pyra)
        KC = number of lines in data card
        N1 = 0 (not used)
        N2 = 0 (not used)
        NODES = number of nodes in the element
        CONFIG = 0 (not used)
        PID = element property ID
        CEID = 0 (not used)
        q1,q2,q3 = 0 (not used)
        LNODES = element corner nodes followed by additional nodes
        ADATA : not used
Packet 03: Material Properties
The material properties packet contains the following:
        3 ID IV KC N1
        DATA
        ADATA

where:  ID = Material ID
        IV = Material type
        KC = number of lines in data card
        DATA = 96 Material property constants (only 82 are used here)
        ADATA = Associated ply data values (not used)

Packet 04: Element Properties

The element properties packet contains the following:
        4 ID IV KC N1 N2 N3 N4
        DATA

where:  ID = Property ID
        IV = Material type
        KC = number of lines in data card = 2
        DATA = 7 element property constants
 
Packet 05: Coordinate Frames

The coordinate frames packet contains the following:
        5 ID IV KC
        A1 A2 A3 B1 B2 B3 C1 C2 C3 R(1,1) R(2,1) ... R(3,3)

where:  ID = Coordinate frame ID

        IV = Coordinate type (1=rectangular, 2=cylindrical, 3=spherical)
        KC = number of lines in data card = 4
        A, B, C = 3 points defining the coordinate frame.
        A = Origin of local coordinate system
        B = Point on local Z-axis
        C = Point on local X-axis
        R       = 3 x 3 rotation matrix to transform coordinates
                  from this frame to the global rectangular frame.

Packet 06: Distributed Loads

The distributed load packet contains the following:
        6 ID IV KC
        LTYPE EFLAG GFLAG ICOMP(6) NODE(8) NFE
        PDATA

where:  ID = element ID
        IV = load set ID
        KC = number of lines in data card
        LTYPE = 1 in 3D for surface load, 0 in 2D for line load
        EFLAG = set to 1 i.e. loads applied on element's faces
        GFLAG = set to 0
        ICOMP = 6 load component flags (1 if loaded, else 0)
        NODE = 8 element corner node flags (1 if loaded, else 0)
        NFE = loaded edge number in 2D or face number in 3D
        PDATA = non-zero load components
Packet 07: Node Forces
The node forces packet contains the following:
        7 ID IV KC
        CID ICOMP(6)
        FDATA

where:  ID = node ID
        IV = load set ID
        KC = number of lines in data card
        CID = coordinate system ID
        ICOMP = 6 force components flags (1 if loaded, else 0)
        FDATA = non-zero load components
Packet 08: Node Displacements
The node displacements packet contains the following:
        8 ID IV KC
        CID ICOMP(6)
        DDATA

where:  ID = node ID
        IV = constraint set ID
        KC = number of lines in data card
        CID = coordinate system ID
        ICOMP = 6 displacement component flags (1 if loaded, else 0)
        DDATA = non-blank displacement components (may be 0.0)
Packet 10: Node Temperature
The node temperature packet contains the following:
        10 ID IV KC N1 N2
        TEMP

where:  ID = node ID
        IV = temperature ID set
        KC = 1
        N1 = data flag (1 if TEMP is a real value, 0 if TEMP is a dummy value)
        N2 = user function ID
        TEMP = temperature
Packet 15: Nodal Heat Source
The nodal heat source packet contains the following:
        15 ID IV KC N1 N2
        NHEAT

where:  ID = node ID
        IV = heat flux ID set
        KC = 1
        N1 = data flag (1 if NHEAT is a real value, 0 if NHEAT is a dummy value)
        N2 = user function ID
        NHEAT = heat flux
Packet 16: Distributed Heat Source
The distributed heat source packet contains the following:
        16 ID IV KC N1 N2 N3
        NFLAG NODE
        DHEAT 

where:  ID = element ID
        IV = distributed heat flux ID set
        KC = 2
        N1 = data flag (1 if DHEAT is a real value, 0 if DHEAT is a dummy value)
        N2 = user function ID
        N3 = dimension code (0 if no DHEAT dimension
                             1 if DHEAT per unit lenght
                             2 if DHEAT per unit area
                             3 if DHEAT per unit volume)
        NFLAG = 0 (one DHEAT value)
        NODE  = 8 element node flags (0 or 1)
        DHEAT = distributed heat flux
Packet 17: Convection Coefficients
The convection coefficients packet contains the following:
        17 ID IV KC N1 N2
        NFLAG NODE
        CONV 

where:  ID = element ID
        IV = convection coefficient ID set
        KC = 2
        N1 = data flag (1 if CONV is a real value, 0 if CONV is a dummy value)
        N2 = user function ID
        NFLAG = 0 (one CONV value)
        NODE  = 8 element node flags (0 or 1)
        CONV = convection coefficient
Packet 18: Radiation Emissivity Values
The radiation emissivity values packet contains the following:
        18 ID IV KC N1 N2
        NFLAG NODE
        EMIS 

where:  ID = element ID
        IV = radiation emissivity ID set
        KC = 2
        N1 = data flag (1 if EMIS is a real value, 0 if EMIS is a dummy value)
        N2 = user function ID
        NFLAG = 0 (one EMIS value)
        NODE  = 8 element node flags (0 or 1)
        EMIS = convection coefficient
Packet 21: Named Component Definition
The named component definition packet contains the following:
        21 ID IV KC
        NAME
        NTYPE(1) ID(1) NTYPE(2) ID(2) ... NTYPE(N) ID(N)

where:  ID = component number
        IV = 2 times the number of data pairs (2*N)
        KC = number of lines in data cards
        NAME = component name
        NTYPE(i) = type of item in component, here only type 5 (node) is used
        ID(i) = node number
Packet 99: End of Neutral File
The end of neutral file packet contains the following:
        99 ID IV KC

where:  ID = 0 (not applicable)
        IV = 0 (not applicable)
        KC = 1
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