Files and Data

Openning a Single File

To open a single data file:

• Click the "open file" icon in the tool window. A dialog window will popup:
  
  
  
• Select ascii (default) or binary file (note that the file formats change if the ascii/binary toggle changes its state).
• Select single file (default).
• If the file sits on a remote host double click on the machine name.
• Double click on a directory name in order to change to that directory.
• Select the file name in the file list.
• Select the file format from the option menu.
• The path to the desired file can be typed in the "name" entry field.
• Click the OK button.
• Check the information printed on the console or in the ouput area of the tools window.

Openning a Set of Parallel Files

  To open a group of files which correspond to a set of subdomains of a parallel calculation:

• Click on the "open file" icon of the tools window. A dialog window will popup:
  
  
  
• Select ascii (default) or binary file (note that the file formats change if the ascii/binary toggle changes its state).
• Select set of files (see figure above).
• If the file sits on a remote host double click on the machine name.
• Double click on a directory name in order to change to that directory.
• In the list of files, select the name of the first file of the set.
• In the "domains" entry field type the number of files to read.
• In the "format" entry field type the number of digits considered to differentiate between different files in the same group (in the above image the file names end with 2 digits representing the domain number).
• Select the file format from the option menu.
• The path to the desired file can be typed in the "name" entry field.
• Click the OK button.
• Check the information printed on the console or in the ouput area of the tools window.


 

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Openning a Project File

  Project files are not implemented yet. They will include: unsteady multidisciplinary parallel set of files.
 

Data-Set Types

 Different kinds of data sets can be read into ZFEM for visualization in different disciplines: discrete data sets, continuous data sets, compressible fluids, incompressible fluids, structural data sets and curves. These data sets can be read from a file in ZFEM format described below or for some cases  directly from FEFLO or NASTRAN files.

Discrete Data Sets

DISCRETE data sets are used for the visualization of particles. The consist in a set of points or particles and a set of fields or values defined at the location of the points. The fields are a set of values specified at the location of each point. Fields can be INTEGER or REAL. For the case of integer fields, a single integer value is specified at each point. Real fields can have any number of real values specified at each point. If the number of values (dimension of the field) equals three the field is recognized as a vector field and can be used for vector plots and traces. Scalar fields (single value at the points) or different components of a real field can be used to create several kinds of plots. Integer fields can also be used to filter points.

The ZFEM file format for discrete data sets consists ina "points" section, where the coordinates of the points are specified, followed by a "fields" section, where any number of integer or real fields can be specified in any order. The format for this kind of data set is:

DISCRETE
data set name
points name
npoints
x1 y1 z1
...
xn yn zn
INTEGER
field name
v1
...
vn
REAL
field name
mdimensions
v11 v12 ... v1m
...
vn1 vn2 ... vnm
END

Continuous Data Sets

CONTINUOUS data sets are used for the visualization of simulations in continuum mechanics (fluids, structures, thermal, electro-magnetics, etc.). These data sets consist in a list of points, a list of fields defined at the points and a set of element lists connecting the points. The fields are a set of values specified at the location of each point. Fields can be INTEGER or REAL. For the case of integer fields, a single integer value is specified at each point. Real fields can have any number of real values specified at each point. If the number of values (dimension of the field) equals three the field is recognized as a vector field and can be used for vector plots and traces. Scalar fields (single value at the points) or different components of a real field can be used to create several kinds of plots. Integer fields can also be used to filter points. Several lists of elements can be defined connecting the points into a grid. Different element types are available: EDGE (connecting 2 points), TRIANGLE (connecting 3 points), QUAD (connecting 4 points), TETRAhedra (connecting 4 points) and BRICK or hexahedra (connecting 8 points). These elements and the internal numbering of the nodes are shown in the following figure:

The ZFEM file format for these kinds of data sets consists in a "points" section, where the coordinates of the points are specified, followed by a "fields" section, where any number of integer or real fields can be specified in any order, followed by an "element" section, where any number of element lists can be specified in any order. The format is:

CONTINUOUS
data set name
points name
npoints
x1 y1 z1
...
xn yn zn
INTEGER
field name
v1
...
vn
REAL
field name
mdimensions
v11 v12 ... v1m
...
vn1 vn2 ... vnm
END_FIELDS
TETRA
element list name
nelements1
p11 p21 p31 p41
...
pn1 pn2 pn3 pn4
TRIANGLE
element list name
nelements2
p11 p21 p31
...
pn1 pn2 pn3
END

CONTINUOUS
data set name
points name
npoints
x1 y1 z1
...
xn yn zn
INTEGER
field name
v1
...
vn
REAL
field name
mdimensions
v11 v12 ... v1m
...
vn1 vn2 ... vnm
END_FIELDS
STRUCTURED
mesh name
nd nx ny [nz]
END

Compressible Fluid Data Set

COMPRESSIBLE fluid data sets are a subset of the continuous data sets. The only difference is that in this case only three real fields are expected: pressure (scalar), velocity (vector) and temperature (scalar).  Other fields are automatically derived from these: absolute value of the velocity (scalar). Other parameters such as the DENSITY can be also specified. The rest of the data set is identical to the   continuous data sets.  The file format for these data sets is then of the form:
 

COMPRESSIBLE
data set name
[GAMMA 1.4]
[CP 1000.0]
[EOS IDEAL]
POINTS
mesh points
npoints
x1 y1 z1
...
xn yn zn
REAL
density
1
d1
...
dn
REAL
velocity
3
v1x v1y v1z
...
vnx vny vnz
REAL
energy
1
e1
...
en
INTEGER
integer name
v1
...
vn
END_FIELDS
TRIANGLE
ntriang
p11 p12 p13
...
pn1 pn2 pn3
END

 If the lines between brackets are not specified the default values shown above are taken.
 

Incompressible Fluid Data Set

 INCOMPRESSIBLE fluid data sets are a subset of the continuous data sets. The only difference is that in this case only three real fields are expected: density (scalar), velocity (vector) and energy (scalar).  Other fields are automatically derived from these: absolute value of the velocity (scalar), pressure (scalar), Mach number (scalar) and temperature (scalar). In order to derive these fields a set of parameters needs to be specified: GAMMA (ratio of specific heats), CP (heat capacity at constant pressure) and the equation of state (EOS). Currently the only equation of state supported is of the type IDEAL gas. Other equations of state will be incorporated in the future. The rest of the data set is identical to the   continuous data sets.  The file format for these data sets is then of the form:
 

INCOMPRESSIBLE
data set name
[DENSITY 1.0]
POINTS
mesh points
npoints
x1 y1 z1
...
xn yn zn
REAL
pressure
1
p1
...
pn
REAL
velocity
3
v1x v1y v1z
...
vnx vny vnz
REAL
temperature
1
T1
...
Tn
INTEGER
integer name
v1
...
vn
END_FIELDS
TRIANGLE
ntriang
p11 p12 p13
...
pn1 pn2 pn3
END

  If the lines between brackets are not specified the default values shown above are taken.
 

Structural Data Set

STRUCTURE  data sets are a subset of the continuous data sets. The only difference is that in this case only two real fields are expected: loads (scalar) and velocity (vector). Other fields are automatically derived from these: absolute value of the velocity (scalar). More fields and derived fields will be included in the future. The rest of the data set is identical to the   continuous data sets.  The file format for these data sets is then of the form:
 

STRUCTURE
data set name
mesh points
npoints
x1 y1 z1
...
xn yn zn
REAL
loads
1
p1
...
pn
REAL
velocity
3
v1x v1y v1z
...
vnx vny vnz
INTEGER
integer name
v1
...
vn
END_FIELDS
TRIANGLE
ntriang
p11 p12 p13
...
pn1 pn2 pn3
END

Curves Data Set

CURVE data sets are used to create XY plots (curves). This kind of data set consist in a set of values defined at a number of points. The values are given in the form of a table where any column can be plotted against any other. The format of the file is:
 

CURVE
data set name
nvalues mpoints
label1
...
laneln
v11 v12 ... v1n
...
vm1 vm2 ... vmn
END
 

File Formats

Data files in several formats can be read into ZFEM. The format is selected in the option menu of the open dialog:

The formats supported are:

• ZFEM: refer to the data types for a description of the ZFEM file formats
• FEFLO surf comp: compressible surface dumps of FEFLO
• FEFLO surf inco: incompressible surface dumps of FEFLO
• FEFLO surf csd: structural dynamics surface dumps of FEFLO
• FEFLO surf: surface dumps of the grid generator of FEFLO (GEN3D)
• FEFLO domn comp: compressible domain (volume) meshes of FEFLO
• FEFLO domn inco: incompressible domain (volume) meshes of FEFLO
• FEFLO domn comp 2d: compressible 2D domains of FEFLO
• FEFLO domn inco 2d: incompressible 2D domains of FEFLO
• NASTRAN:
• single NASTRAN domain file:


recognized keywords: GRID*, CTRIA2, CTRIA3, CQUAD2, CQUAD4, CIHEX1

• set of NASTRAN files:
• a file that begins with the keyword ZNASTRAN
• the name of the NASTRAN domain file
• the name of other NASTRAN field files:


recognized keywords: QHDBY*, FORCE*, TEMP*, G (displacement files)

For more information refer to the FEFLO and NASTRAN documentation.

Controling Open Projects

Any number of projects (single data files or sets of parallel files) can be open simultaneously with ZFEM. Clicking the "manage projects" icon in the tools windows opens the following dialog window:

The upper half of the split window shows the currently open projects with their name and host computer. A project can be made active by selecting it from this list. The active project is the one responding to any request to create a plot or perform a calculation. The active project can be closed by clicking the delete icon on the top left of the window. The lower part of the split window shows some information about the active project.

Controling Data Sets

Within a given project, several data sets may be present. For example, from the original data set read from the file(s), new data sets such as  cut-planes, iso-surfaces or deformation surfaces can be computed. These data sets contain their own set of points, fields and elements. From these new data sets different plots can be created. Click on the "manage data" icon in the tools window to open the following dialog window:

This window shows all the available data sets within the active project. The selected data set can be deleted by clicking the delete icon, or saved into a file in ZFEM format, either in ascii (default) or binary mode. The name of the file must be typed in the text entry field. If the project consists in a set of files (parallel application) the domain number will be appended to the file name of each subdomain.