Name

join — Connect nodes

Synopsis

join id
  attributes...
end

Description

The join command specifies equality between the dof's of joined nodes. This set is identified by id, a non-negative integer which must be unique for the join conditions of the current model. id is the number which is referenced by the join option of the case definition. Sets with an id of 0 will be active for all analysis cases.

The join command is required if more than one branch is defined and the branches are to be connected or if nodes of the same branch are to be connected explicitly. Note that the same effect can be obtained by specifying linear constrains, see linc command, although on a dof by dof base).

The join command must be issued after all nodes and elements have been specified.

Attributes

delta v

Specifies the threshold value v in global x-, y- and z-direction for comparing nodes (relevant for the automatic parameter only). This option must be issued before automatic in order to take effect. If not specified, the threshold value will be computed as a function of the bounding box.

automatic

Establishes the node connectivity automatically by comparing node positions. The nodes are transformed to the global-global coordinate system. If the nodes are close enough (see delta parameter) they will be linked. Note that the node and dof commands may not be specified if automatic is selected. No other parameter can be specified after the automatic option.

Data

node br1 node1 br2 node2

Generates links node-wise. Node node1 of branch br1 is linked to node node2 of branch br2. The automatic command may not be specified if node is selected. Branch and node numbers are external.

dof br1 node1 dof1 br2 node2 dof2

Generates links between degrees-of-freedom. The degree-of-freedom dof1 of node node1 of branch br1 is connected to the degree-of-freedom dof2 of node node2 of branch br2. Branch and node numbers are external. degree-of-freedom numbers are positive integers.

Example

The most common use of join is:

join 0
  automatic
end

Additional notes

Master nodes are automatically determined as follows: The node belonging to the lower branch number in the link list (see node and from parameters) becomes the master node.

For automatically computed link lists, the node lists are compared branch-wise and in ascending order (internal branch numbering). The first encountered node that matches another node in the list becomes the master node. The matching criteria are defined by a cube of size (delta, delta, delta) constructed around the node.