3.1.15. region Command

This command labels a group of nodes and/or elements as a mesh region. Regions are used to assign Rayleigh damping factors to selected parts of the model. A region is defined by elements or by nodes, not both.

If elements are specified, the region includes those elements and their connected nodes unless -eleOnly is used. If nodes are specified, the region includes those nodes and all elements whose nodes are all in the region, unless -nodeOnly is used.

region $regTag <$selectionOptions> <-rayleigh $alphaM $betaK $betaKinit $betaKcomm>

Argument	Type	Description
$regTag	integer	unique region tag
-ele	string	flag followed by a list of element tags
-eleOnly	string	same as -ele but connected nodes are not included
-eleRange	string	flag followed by $startEle and $endEle
-eleOnlyRange	string	element range with -eleOnly behavior
-node	string	flag followed by a list of node tags
-nodeOnly	string	same as -node but connected elements are not included
-nodeRange	string	flag followed by $startNode and $endNode
-nodeOnlyRange	string	node range with -nodeOnly behavior
-rayleigh	string	flag followed by Rayleigh damping factors: $alphaM $betaK $betaKinit $betaKcomm

Note

The user cannot define a region using both element and node selection flags in the same command.

Example

1. Tcl Code

region 1 -ele 1 5 -eleRange 10 15
region 2 -node 2 4 6 -nodeRange 9 12 -rayleigh 0.0 0.01 0.0 0.0

2. Python Code

ops.region(1, '-ele', 1, 5, '-eleRange', 10, 15)
ops.region(2, '-node', 2, 4, 6, '-nodeRange', 9, 12, '-rayleigh', 0.0, 0.01, 0.0, 0.0)

Code Developed by: fmk