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*NODES
Data format:
An arbitrary number of lines comprising 8 values each
NO IDOF X Y Z XR YR ZR
Status :
Required
Purpose :
To define initial co-ordinates of the nodes (implicitly defining the length unit of the model)
Restriction :
The number of nodes may not exceed the value of parameter MAXNOE which is version dependent
Details :
| Parameter | Description |
|---|---|
| NO | Identification number of the node |
| IDOF | 6 digit integer concatenation used to assign degrees of freedom to the node. The first 3 digits refer respectively to the X,Y and Z translations, the other 3 are related to the X,Y and Z rotations. The values are as follows : 0 - The node is free to move in the corresponding direction 1 - The corresponding displacement is prescribed either directly in a dynamic simulation or because the node is a slave one (see example below). 2 - No movement is allowed in the corresponding direction (locked dof). Note that nodes connected only to cable elements may not have their rotational dofs released (this would generate null diagonal terms in the stiffness matrix). If necessary, the program modifies the dofs of the nodes connected only to cable elements |
| X,Y,Z | Initial co-ordinates of the nodes. Those values are taken as initial configuration for static calculations. It is strongly recommended to avoid unrealistic configurations that could prevent convergence . This is particularly true for stiff cable elements (the length of which are defined in *CABPRO) where a small error in the node co-ordinates may lead to a very high initial tension. |
| XR,YR,ZR | Initial rotation around X,Y and Z local axes (only for master nodes). |
Note
The degrees of freedom are numbered by the program in their order of appearance . An automatic renumbering is performed starting with node number 1 and minimising the system's bandwidth . The keyword *BANDOP may be used to specify another initial front for this renumbering leading to a smallest bandwidth.
Example:
*NODES
cNO IDOF X Y Z XR YR ZR
1 111000 -6.00 8.40 16.40 0. 0. 0.
11 000000 56.20 0.00 -47.10 0. 0. 0.
12 222222 56.20 0.00 -77.10 0. 0. 0.
18 222222 102.70 7.62 -77.10 0. 0. 0.
Node 1 has a transitional motion imposed in the three directions. Its rotational motions are free. Node 11 is completely free, which means 6 degrees of freedom. If the elements bound to node 11 are cables, the rotational dof's will automatically be put to the value 2 since there are neither torsion nor flexion. Nodes 12 and 18 are fixed and their IDOF are 222222.
