Ansys Nodes and Elements

After you write the ET, R, and MP statements, you define the node locations, select one combination of ET, R, and MP, and then define the elements.

• The Nodes: Node locations are defined with the N command which has at least two options. The first option is the node number. The next three options are the X, Y, and Z values of the node. Zero values can be omitted. The command looks like this:

```        N,1,x,y,z       ! Node 1 at (x,y,z)
N,1,0           ! Node 1 at (0,0)
N,5,10          ! Node 5 at (10,0)
FILL,1,5        ! NODES 2,3,4 equally spaced
N,6,(10+8)      ! Node 6 at (18,0)```
You can also define a sequence of nodes with the NGEN command.

• The FILL command, as shown above, creates linearly spaced nodes between the nodes given in the first and second option. Additional options let you skip nodes. The third option is the number of new nodes, the fourth option is the number of the first new node, and the fifth option is the node number increment. For example:

```       FILL,1,9           ! create nodes 2 to 8 equal spaced
FILL,1,41,3,11,10  ! bottom edge```

The second command creates three nodes. They are equally spaced between nodes 1 and 41. The new nodes are numbered 11, 21, and 31.

• The TYPE, REAL, and MAT Commands: Before you can define an element, you must link it to the ET, R, and MP tables. This is done with the TYPE, REAL, and MAT commands which have one option matching the corresponding entry in the ET, R, or MP tables. For example, the lines:

```        TYPE,1
REAL,2
MAT,1```

prepare for an element with properties corresponding to the previously defined

```        ET,1
R,2
MP,XX,1```
where XX is EX or one of other first options to MP.

• The Elements: The element command has options giving the corresponding node numbers. For a one-dimensional element, the two end nodes are given. For a triangular node, the three options are the nodes in counterclockwise order. For example, the following lines:

```        TYPE,1           ! ET 1
MAT,1            ! MP 1
REAL,1           ! Shape 1
E,1,2            ! Element 1, nodes 1-2
E,2,3            ! Element 2, nodes 2-3
REAL,2           ! Shape 2
E,3,4            ! Element 3, nodes 3-4```

create three elements all with properties defined by TYPE 1 and MP 1. The first two elements have the same real properties, such as area, while the third element has a different value. The first two elements, from nodes 1 to 2 and from nodes 2 to 3, have the property defined by R 1. The third element, from nodes 3 to 4, has the property defined by R 2. The TYPE, MAT, and REAL commands continue in effect until another one appears. Do no use TYPE 1 if the previous the previous TYPE command is also 1.

You can also define a sequence of elements with the EGEN command.

MENG 421 -- Source Program -- NGEN and EGEN -- Element-Property Tables -- Ansys index -- Class assignments