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015-Using Tables in ANSYS

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015-Using Tables in ANSYS Powered By Docstoc
					George Ellwood CCLRC 


                               Using Tables in ANSYS
ANSYS reads in tables of values as tab delimited txt files. In most examples ANSYS
wants a coordinate and then a value at that coordinate. An example is shown in figure
1.1a & b, this is for a 2D table with primary variable x and secondary variable y.

                 Figure 1.1a Example of a 2D table opened in Notepad




                                 Figure1.1b Explanation




The primary variable, x in this case, is highlighted in the black box. The secondary
variable, y in this case, is highlighted in the red box. At the point x=2, y=3 the value is
80.

For a 3D table ANSYS needs more information, it requires the x-y plane information at
different off sets of z. As shown in figure1.2.

                                   Figure 1.2: 3D table
George Ellwood CCLRC 


Figure 1.3a & b shows how this looks when opened in notepad.

                          Figure 1.3a: 3D table opened in Notepad




                                  Figure 1.3b Explanation




The primary variable is highlighted in the black box. The secondary variable in the red
box. The third variable in the green box.

Creating Tables from Excel
Large tables can be created simply by using excel. Data manipulation can be
performed here and then the final table can be transferred back into ANSYS. For this
example a 3D table will be created. The table comprises values at positions in the x-y
plane at two different positions of z. These are shown in table 2.1.

                          Table 2.1: Values at different coordinates

Z=0                                             Z=1

              y                                             y

          0       1   2                                 0       1   2

      0   5   10 15                                   0 50 55 60
 x                                               x
      1 20 25 30                                      1 65 70 75

      2 35 40 45                                      2 80 85 90
George Ellwood CCLRC 


Figure 2.1 shows how table needs to be represented in excel in order for the file to be
readable for ANSYS.

                        Figure 2.1:Excel representation of table




A break down of what this means is shown in figure 2.2. The first variable, x in this
case, is shown in blue. The second variable, y, is shown in red, these form the x-y
coordinates, the grid shows the values at these positions. The z coordinate is shown
in brown. This is in the top left hand corner. For multiple values of z this grid is
repeated but the z value is changed, as shown in figure 2.1. The values of the x, y and
z are free to change between planes. The formatting must be that shown in figure 2.1
or there may be problems interpreting the file in ANSYS.

                        Figure 2.2: Explanation of table spacing
George Ellwood CCLRC 




Once the table has been created in excel it needs to be saved as a .txt file. These are
tab delimited text files. It should be saved in the working directory that ANSYS will be
using. In this example it has been saved as tabletest.txt. Excel may give a few
warnings when saving but just click ok to carry on. The text file can be opened in a
text editor such as notepad. This is shown in figure 2.3.

                      Figure 2.3: tabletest.txt viewed from notepad




In the macro or the command window on ANSYS type the following commands.

*DIM,Txyz,table,3,3,2,x,y,z

*TREAD,Txyz,tabletest,txt,,

The first line tells ANSYS to create a table array called Txyz that is 3 x 3 x 2. With the
first variable x, second variable y and third variable z.

The second line tells ANSYS to read the values from tabletest into the Txyz table.

You can check that the table has been created correctly by going to
Parameters>Array Parameters>Define/Edit

Choose the table you want to look and click edit.

This will then display the table and you can confirm it has been created correctly.

				
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