Set records

A set specifies a region of the geometry as a combination of volumes, surfaces, edges and nodes. Sets are used above all to attach a region of elements to a cross section, or to apply a boundary condition, but they have many other uses.

Record syntax

Set num (in) [elements (ia)] [elementranges (rl)] [allElements] [nodes (ia)] [noderanges (rl)] [allNodes] [elementboundaries (ia)] [elementedges (ia)] [elementsurfaces (ia)] [internalelementnodes (ia)] <ver. 1.6> [dofmanprops (s)] [elemprops (s)]

Volumes and nodes

[elements (ia)], [nodes (ia)]

Explicit lists of element, respectively node, numbers.

[elementranges (rl)], [noderanges (rl)]

The same, given as range lists; see Attribute types.

[allElements], [allNodes]

Flags selecting every element, respectively every node, in the domain.

Edges and surfaces

[elementedges (ia)], [elementboundaries (ia)], [elementsurfaces (ia)]

Interleaved lists in which every other number is the element number and the one after it the edge, boundary or surface number. The total length of the list is therefore twice the number of entities. The internal numbering of edges and surfaces is given in the Element Library Manual.

[internalelementnodes (ia)]

Interleaved list of element number and internal node number, for elements that manage internal dof managers.

Which entity kind to use

The entity kind must match the dimensionality of what is applied to it:

• bulk loads, in newtons per volume, belong on elements;

• surface loads, in newtons per area, belong on elementboundaries;

• edge loads — singular loads in newtons per length, or the equivalent — belong on elementedges.

Example 1. A deadweight (gravity) load is applied to the elements of a set, while a distributed line load is applied to the midline “edge” of a beam element and therefore belongs to an elementedges set. In the latter case the midline of the beam is defined as the first — and only — “edge” of the beam.

Example 2. In an axisymmetric structural analysis a deadweight load is applied to the elements of a set, while an external pressure is defined as a surface load and applied to the elementboundaries of a set. The element integrates the load analytically around the axis, so it still counts as a surface load.

Properties set through a set

Arbitrary dof manager and element properties can be assigned through a set (supported from version 1.6).

[dofmanprops (s)]

A string of dof manager parameters, applied to every dof manager in the set.

[elemprops (s)]

A string of element parameters, applied to every element in the set.

The syntax inside these strings is the ordinary input record syntax.

Note

Parameters defined this way have the lowest priority: they are overridden by the parameters given in the individual dof manager or element records. See tests/regression/sm/setprops01.in for an example.