Flexcom > Data Inputs > $MODEL

Purpose

To specify nodes at particular locations along a cable, or to specify a number of equally spaced nodes along a cable segment between two nodes.

Theory

Refer to Defining Nodes in Terms of Cables for further information on this feature.

Note also that the old *NODE, *ELEMENT and *CABLE keywords have been largely superseded by the new *LINES keyword. Lines provide an automatic mesh creation facility to greatly expedite the model creation process. Using lines is a fundamentally different approach to working directly with nodes, elements and cables, although the information is ultimately handled in the same fashion internally. Since lines provide automatic mesh generation, you do not to concern yourself with explicit node and element numbering. Indeed the availability of lines makes nodes, elements and cables redundant to some degree, but they are retained for complete generality, and also to maintain downward compatibility with previous program versions. Refer to Lines for further information on this feature.

Keyword Format

Two types of lines that may be repeated as often as necessary.

Line defining a single node on a cable:

Node (Number or Label), Cable no., Distance Along Cable

Line generating a number of nodes along a cable.

CURV=Start Node (Number or Label), End Node (Number or Label) [, Node Increment] , CABLE=Cable No.

Any cable numbers used must be defined under *CABLE. If you specify a node label rather than a node number, it must be enclosed in {} brackets. Node Increment defaults to 1.

Table Input

Cables - Define Nodes

Input:	Description
Node:	The node (number or label) being defined. If you specify a node label rather than a node number, it must be enclosed in {} brackets.
Cable Number:	The number of the cable on which the node is being defined.
Distance Along Cable:	The distance along the cable measured from the start node to the node being defined

Cables – Generate Nodes

Input:	Description
Start Node:	The node (number or label) at the start of the cable segment. If you specify a node label rather than a node number, it must be enclosed in {} brackets.
End Node:	The node (number or label) at the end of the cable segment. If you specify a node label rather than a node number, it must be enclosed in {} brackets.
Cable Number:	The number of the cable along which the nodes are being generated.
Node Increment:	The node number increment to be used in assigning numbers to the generated nodes. This input defaults to a value of 1, which will apply in the majority of cases

Notes

(a)The Cables - Define Nodes option is commonly used for mesh refinement on a cable.

(b)Node numbers are assigned to generated nodes by repeatedly adding the specified or default increment to the previous number (obviously starting at the start node) until the end node number is reached or exceeded. So for example, the specification Start Node - 1, End Node - 11, Increment - 2 will result in 4 nodes, numbered 3, 5, 7 and 9, and dividing the cable between Nodes 1 and 11 into 5 equal segments.