MeshPoint
, so a mesh point which can be found in domain.getTopology().getPointSet()
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Node selections are used to apply boundary conditions (Prescribed Displacements) or to extract curves (Saving history curves to disk) on a specific node set which does not initially come from a geometric entity. In Metafor, a selection is represented by a Group
. This object is a virtual geometric entity which can possess nodes, in the same way as other entities receive them when they are meshed.
A Group
is defined as any other geometric entity.
groupset.add( Group(number) )
Some functions can be used to obtain data on some nodes of a Group
:
grp = groupset(number) grp.getNo() # Returns the number of the group grp grp.getNumberOfMeshPoints() # Returns the number of meshedPoints in the ''Group'' grp grp.getMeshPoint(idx) # Returns a reference towards the idxth MeshedPoint of the group grp.
groupset(number).add(GObject) groupset(number).addMeshPoint(no) groupset(number).addMeshPointsInBox(xmin, xmax, ymin, ymax, zmin, zmax) groupset(number).addMeshPointsFromObject(target, selector)
where
number | group number |
no | number of the node 1) to add to the group |
xmin , ymin , zmin | lower corner of the selection box |
xmax , ymax , zmax | upper corner of the selection box |
target | geometric entity used as support |
selector | selection operator which reduces the number of MeshPoints in the group |
It is not always easy to select only the required nodes (on parametric studies for example). Therefore, it is possible to sort a selection, in order to select a subset of this first selection. This is done done with Node Sorting Operators.
groupset(number).selectMeshPoints(sorter,nbMeshPoints)
where
number | group number |
sorter | sorting operator |
nbMeshPoints | number of MeshPoints which will remain in the group |
Example:
group.addMeshPointsFromObject(sideset(1)) group.selectMeshPoints(SortByNo(),3)
These lines sort the nodes by user number and conservation of three values.
Adding nodes from the geometric object target
:
groupset(number).addMeshPointsFromObject(target, selector)
where selector
is an object of the Selector
type. Here are some of its derived classes:
BoxSelector
(selection within a bow),RangeSelector
(selection in a given area),DistSelector
(spherical selection),SectorSphericalSelector
(selection in a spherical sector),AnnealedSelector
(selection of a ring along the x
, y
or z
direction),SectorAnnealedSelector
(selection of a part or a ring, defined by two angles, along the x
, y
or z
direction),InverseSelector
(inverse the selection criterion passed in argument).Examples:
group.addMeshPointsFromObject(sideset(1), RangeSelector(TX, xmin, xmax))
gets all nodes from side #1 whose x
coordinate is between xmin
et xmax
.
group.addMeshPointsFromObject(sideset(1), BoxSelector(xmin, xmax, ymin, ymax, zmin, zmax))
gets all nodes from side #1 in the rectangular box defined by xmin
, xmax
, ymin
, ymax
, zmin
, zmax
.
group.addMeshPoints(DistSelector(x, y, z, R))
gets all nodes situated in a sphere of center (x,y,z)
and radius R
.
group.addMeshPoints(SectorSphericalSelector(Cx, Cy, Cz, rMin, rMax, thetaMin, thetaMax, phiMin, phiMax))
gets all nodes in the spherical sector of center (Cx,Cy,Cz), of minimal and maximal radii rMin and rMax, of minimal and maximal azimuth angle thetaMin and thetaMax, and of minimal and maximal elevation angle pHiMin and phiMax.
Note : angles are computed with respect to the structural frame translated toward the center or the sphere. The elevation angle varies from $-\frac{\pi}{2}$ to $\frac{\pi}{2}$ and the azimuth angle from $0.0$ to $2 \pi$.
group.addMeshPoints(AnnealedSelector(TX, x, y, z, rMin, rMax, zMin, zMax))
gets all nodes situated from the two cylinders of axis TX
, of radii rMin
and rMax
, and of height between zMin
and zMax
.
group.addMeshPoints(SectorAnnealedSelector(TX, x, y, z, rMin, rMax, thetaMin, thetaMax, zMin, zMax))
gets all nodes situated within two parts of cylinders of axis TX
, of opening angle between thetaMin
and thetaMax
, of radii rMin
and rMax
, and of height between zMin
and zMax
.
MeshPoint
, so a mesh point which can be found in domain.getTopology().getPointSet()