ansys.mapdl.core.Mapdl.nsel#

Mapdl.nsel(type_='', item='', comp='', vmin='', vmax='', vinc='', kabs='', **kwargs)#

Selects a subset of nodes.

Mechanical APDL Command: NSEL

Parameters:

type_str

Label identifying the type of select:

S - Select a new set (default).
R - Reselect a set from the current set.
A - Additionally select a set and extend the current set.
U - Unselect a set from the current set.
ALL - Restore the full set.
NONE - Unselect the full set.
INVE - Invert the current set (selected becomes unselected and vice versa).
STAT - Display the current select status.

itemstr

Label identifying data. Valid item labels are shown in the table below. Some items also require a component label. If Item = PICK (or simply “P”), graphical picking is enabled and all remaining command fields are ignored (valid only in the GUI). Defaults to NODE.

compstr

Component of the item (if required). Valid component labels are shown in the table below.

vminstr

Minimum value of item range. Ranges are node numbers, set numbers, coordinate values, load values, or result values as appropriate for the item. A component name (as specified on the cm command) may also be substituted for VMIN ( VMAX and VINC are ignored).

vmaxstr

Maximum value of item range. VMAX defaults to VMIN for input values. For result values, VMAX defaults to infinity if VMIN is positive, or to zero if VMIN is negative.

vincstr

Value increment within range. Used only with integer ranges (such as for node and set numbers). Defaults to 1. VINC cannot be negative.

kabsint or str

Absolute value key:

0 - Check sign of value during selection.
1 - Use absolute value during selection (sign ignored).

Notes

Warning

This function contains specificities regarding the argument definitions. Please refer to the command documentation for further explanations.

Selects a subset of nodes. For example, to select a new set of nodes based on node numbers 1 through 7, use nsel,S,NODE,,1,7. The subset is used when the ALL label is entered (or implied) on other commands, such as nlist,ALL. Only data identified by node number are selected. Data are flagged as selected and unselected; no data are actually deleted from the database.

When selecting nodes by results, the full graphics value is used, regardless of whether PowerGraphics is on.

Solution result data consists of two types, 1) nodal degree of freedom–results initially calculated at the nodes (such as displacement, temperature, pressure, etc.), and 2) element–results initially calculated elsewhere (such as at an element integration point or thickness location) and then recalculated at the nodes (such as stresses, strains, etc.). Various element results also depend upon the recalculation method and the selected results location ( avprin, rsys, force, layer and shell ).

You must have all the nodes (corner and midside nodes) on the external face of the element selected to use Item = EXT.

This command is valid in any processor.

For Selects based on non-integer numbers (coordinates, results, etc.), items that are within the range VMIN- Toler and VMAX+ Toler are selected. The default tolerance Toler is based on the relative values of VMIN and VMAX as follows:

If VMIN = VMAX, Toler = 0.005 x VMIN.
If VMIN = VMAX = 0.0, Toler = 1.0E-6.
If VMAX ≠ VMIN, Toler = 1.0E-8 x (VMAX-VMIN).

Use the SELTOL seltol command to override this default and specify Toler explicitly.

NSEL - Valid Item and Component Labels#

Valid Item and Component Labels nsel, `Type,Item,Comp,VMIN,VMAX,VINC,KABS`#
Valid item and component labels for input values are:
Item	Comp	Description
NODE		Node number.
EXT		Nodes on exterior of selected elements (ignore remaining fields).
LOC	X, Y, Z	X, Y, or Z location in the active coordinate system.
ANG	XY, YZ, ZX	THXY, THYZ, or THZX rotation angle.
M		Master node number.
CP		Coupled set number.
CE		Constraint equation set number.
D	U	Any of X, Y, or Z structural displacements. Amplitude only, if complex.
“	UX, UY, UZ	X, Y, or Z structural displacement. Amplitude only, if complex.
“	ROT	Any of X, Y, or Z structural rotations. Amplitude only, if complex.
“	ROTX, ROTY, ROTZ	X, Y, or Z structural rotation. Amplitude only, if complex.
“	TEMP, TBOT, TE2, TE3,…, TTOP	Temperature.
“	PRES	Pressure (for example, PRES degree of freedom for acoustic elements).
“	VOLT	Electric potential.
“	MAG	Magnetic scalar potential.
“	V	Any of X, Y, or Z fluid velocities.
“	VX, VY, VZ	X, Y, or Z fluid velocity.
“	AZ	2D magnetic vector potential. Amplitude only, if complex.
“	CURR	Current.
“	EMF	Electromotive force drop.
F	F	Any of X, Y, or Z structural forces. Amplitude only, if complex.
“	FX, FY, FZ	X, Y, or Z structural force. Amplitude only, if complex.
“	M	Any of X, Y, or Z structural moments. Amplitude only, if complex
“	MX, MY, MZ	X, Y, or Z structural moment. Amplitude only, if complex.
“	HEAT, HBOT, HE2, HE3,…, HTOP	Heat flow.
“	FLOW	Fluid flow.
“	AMPS	Current flow.
“	FLUX	Magnetic flux.
“	CSGZ	Magnetic current segment component. Amplitude only, if complex.
“	CHRG	Electric charge.
“	CHRGD	Electric charge density.
BF	TEMP	Nodal temperature.
“	FLUE	Nodal fluence.
“	HGEN	Nodal heat generation rate.
“	JS	Any of X, Y, or Z current densities. Amplitude only, if complex.
“	JSX, JSY, JSZ	X, Y, or Z current density. Amplitude only, if complex.
“	MVDI	Magnetic virtual displacements flag.
“	DGEN	Nodal diffusing substance generation rate.

NSEL - Valid Item and Component Labels for Nodal DOF Result Values#

Item	Comp	Description
U	X, Y, Z, SUM	X, Y, or Z structural displacement or vector sum.
ROT	X, Y, Z, SUM	X, Y, or Z structural rotation or vector sum.
TEMP		Temperature.
PRES		Pressure.
VOLT		Electric potential.
MAG		Magnetic scalar potential.
V	X, Y, Z, SUM	X, Y, or Z fluid velocity or vector sum.
A	X, Y, Z, SUM	X, Y, or Z magnetic vector potential or vector sum.
CONC		Concentration.
CURR		Current.
EMF		Electromotive force drop.

NSEL - Valid Item and Component Labels for Element Result Values#

Item	Comp	Description
S	X, Y, Z, XY, YZ, XZ	Component stress.
“	1, 2, 3	Principal stress.
“	INT, EQV	Stress intensity or equivalent stress.
EPTO	X, Y, Z, XY, YZ, XZ	Component total strain (EPEL + EPPL + EPCR).
“	1,2,3	Principal total strain.
“	INT, EQV	Total strain intensity or total equivalent strain.
EPEL	X, Y, Z, XY, YZ, XZ	Component elastic strain.
“	1, 2, 3	Principal elastic strain.
“	INT, EQV	Elastic strain intensity or elastic equivalent strain.
EPPL	X, Y, Z, XY, YZ, XZ	Component plastic strain.
“	1,2,3	Principal plastic strain.
“	INT, EQV	Plastic strain intensity or plastic equivalent strain.
EPCR	X, Y, Z, XY, YZ, XZ	Component creep strain.
“	1,2,3	Principal creep strain.
“	INT, EQV	Creep strain intensity or creep equivalent strain.
EPTH	X, Y, Z, XY, YZ, XZ	Component thermal strain.
“	1, 2, 3	Principal thermal strain.
“	INT, EQV	Thermal strain intensity or thermal equivalent strain.
EPSW		Swelling strain.
EPDI	X, Y, Z, XY, YZ, XZ	Component diffusion strain.
“	1, 2, 3	Principal diffusion strain.
“	INT, EQV	Diffusion strain intensity or diffusion equivalent strain.
NL	SEPL	Equivalent stress (from stress-strain curve).
“	SRAT	Stress state ratio.
“	HPRES	Hydrostatic pressure.
“	EPEQ	Accumulated equivalent plastic strain.
“	PSV	Plastic state variable.
“	PLWK	Plastic work/volume.
CONT	STAT NSELcontstat	Contact status.
“	PENE	Contact penetration.
“	PRES	Contact pressure.
“	SFRIC	Contact friction stress.
“	STOT	Contact total stress (pressure plus friction).
“	SLIDE	Contact sliding distance.
TG	X, Y, Z, SUM	Component thermal gradient or vector sum.
TF	X, Y, Z, SUM	Component thermal flux or vector sum.
PG	X, Y, Z, SUM	Component pressure gradient or vector sum.
EF	X, Y, Z, SUM	Component electric field or vector sum.
D	X, Y, Z, SUM	Component electric flux density or vector sum.
H	X, Y, Z, SUM	Component magnetic field intensity or vector sum.
B	X, Y, Z, SUM	Component magnetic flux density or vector sum.
CG	X, Y, Z, SUM	Component concentration gradient or vector sum
DF	X, Y, Z, SUM	Component diffusion flux density or vector sum
FMAG	X, Y, Z, SUM	Component electromagnetic forces or vector sum.

For more information on the meaning of contact status and its possible values, see Reviewing Results in POST1