PSMESH, SECID, Name, P0, Egroup, NUM, KCN, KDIR, VALUE, NDPLANE, PSTOL, PSTYPE, ECOMP, NCOMP
Create and mesh a pretension section
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SECID Unique section number. This number must not already be assigned to a section.
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Name Unique eight character descriptive name, if desired.
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P0 Pretension node number. The node will be defined if it doesn't exist and the number defaults to the highest node number plus one.
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Egroup,NUM Element group on which PSMESH will operate. If
Egroup= P, graphical picking is enabled andNUMis ignored (valid only in the GUI).L (or LINE)
—
PSMESH operates on all elements in the line specified by
NUM. New pretension nodes are associated withNUMor entities below it. Any subsequent LCLEAR operation ofNUMdeletes the pretension elements and nodes created by PSMESH.A (or AREA)
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PSMESH operates on all elements in the area specified by
NUM. New pretension nodes are associated withNUMor entities below it. Any subsequent ACLEAR ofNUMdeletes the pretension elements and nodes created by PSMESH.V (or VOLU)
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PSMESH operates on all elements in the volume specified by
NUM. New pretension nodes are associated withNUMor entities below it. Any subsequent VCLEAR ofNUMdeletes the pretension elements and nodes created by PSMESH.P
—
PSMESH operates on elements selected through the subsequent picking operations, and
NUMis ignoredALL
—
The command operates on all selected elements, and
NUMis ignored.-
KCN Coordinate system number for the separation surface and normal direction.
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KDIR Direction (x, y, or z) normal to separation surface in the
KCNcoordinate system.If
KCNis cartesian, the pretension section normal will be parallel to theKDIRaxis regardless of the position of the pretension node.If
KCNis non-cartesian, the pretension section normal will be aligned with theKDRdirection of systemKCNat the position of the pretension node.-
VALUE Point along the
KDIRaxis at which to locate the separation surface. Ignored ifNDPLANEis supplied.-
NDPLANE Existing node that PSMESH will use to locate the separation surface. If
NDPLANEis supplied, the location of the separation surface is defined by theKDIRcoordinate ofNDPLANE.-
PSTOL Optional tolerance below
VALUE. Allows nodes occurring precisely at or slightly below the separation to be identified properly as above the plane. Has the effect of shifting the plane down byPSTOL. The following expression represents the default value:where ΔX, ΔY, and ΔZ are the dimensions of the model based on nodal locations (that is, ΔX = X
max- Xmin).-
PSTYPE If specified, this value is the type number for pretension elements. (If not specified, ANSYS defines this value.) If already defined, it must be of type PRETS179.
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ECOMP If specified, the name of a component to be composed of new pretension elements and existing elements modified by the PSMESH command.
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NCOMP Name of a component to be composed of nodes on new pretension elements.
Notes
The PSMESH command creates a pretension section
normal to the pretension load direction by cutting the mesh along
existing element boundaries at the point defined by VALUE or NDPLANE and inserting PRETS179 elements. The PSMESH command
verifies that PSTYPE is PRETS179; if it is not, the command finds the lowest available ITYPE that is PRETS179, or
if necessary will create a new one.
When it is necessary to define the pretension node, ANSYS uses
node NDPLANE. If the NDPLANE value is not specified, ANSYS defines the pretension node at:
The centroid of geometric entity
NUM, ifEgroup= LINE, AREA or VOLUThe centroid location of all selected elements, if
Egroup= ALL or if graphical picking is used.
If the elements to which the pretension load is to be applied have already been meshed in two groups, PSMESH cannot be used to insert the pretension elements. The EINTF command must be used to insert the PRETS179 elements between the two meshed groups.
The PSMESH operation copies any nodal temperatures you have defined on the split surface of the original mesh from the original nodes to the newly created coincident duplicate nodes. However, displacements, forces, and other boundary conditions are not copied.
By mathematical definition, the pretension surface must always
be a flat plane. In a non-Cartesian coordinate system, the PSMESH command creates that plane at the indicated position,
oriented with respect to the specified direction of the active system
(in the same manner that the NROTAT command orients
a nodal system with respect to a curved system). For example, assuming
a X = 1 and Y = 45 in a cylindrical coordinate system with Z as the
axis of rotation (KCN = 1), a pretension
surface normal to X tilts 45 degrees away from the global X axis.
The PSMESH command is valid for structural analyses only.