Name

nodes — Nodes definition block

Synopsis

nodes
  attributes
  list ...
  attributes
  list ...
end

Description

The nodes command specifies individual mesh nodes.[6] Node coordinates are specified in the branch coordinate system if defined, otherwise, they are defined in the global coordinate system. Node-local coordinate systems affect only the degrees-of-freedom.

Attributes

dof_ref id

Calculates the node-local DOF (degree-of-freedom) reference frame from the transformation defined by the index id, for the DOF's of subsequently defined nodes. id must be a positive integer referencing the transformation defined by the transformations command. By setting id to 0, any node-local DOF reference-frame is inactivated for all subsequently defined nodes, which is also the default.

Node list

id x y z

Specifies a single node by specifying the node identifier id and the three coordinate components x, y, and z. The node identifier id must be a positive integer number, and it must be unique for the current branch. Notice that B2000++ always works in a 3-dimensional system and therefore 3 coordinate components are required.

Assigning and Changing Attributes

Node attributes may be specified after the definition of the nodes, and node attributes may be changed anytime. To this end, the nodes whose attributes shall be set or changed need to be defined in nodelists and nodesets.

Synopsis:

nodes
  list ...
end

...

nodeset abc
  ...
end

nodes
  dof_ref 2 nodeset abc
end

Additional notes

The nodes command may be specified more than once.

Natural boundary conditions (see nbc command) and essential boundary conditions (see ebc command), when applied to the degrees-of-freedom (default) and the local coordinate system (default) refer to the coordinate system defined here. Consequently, if boundary conditions are to be defined in local coordinates, specify dof_ref for all nodes with local coordinate systems.

Example

Define the nodes 1001, 2002, 1003, and 1004. Node 1002 has a local DOF reference frame identified by the transformation 23:

nodes
  1001 10. 0. 0.
  dof_ref 23
  1002 20. 0. 0.
  dof_ref 0
  1003 30. 0. 0.
  1004 40. 0. 0.
end



[6] Nodes and elements with predefined geometric shapes can be generated instead using the epatch command