SPC1

Bulk Data Entry

SPC1 – Single-Point Constraint, Alternate Form

Description

Defines sets of single-point constraints and thermal boundary conditions.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
SPC1	SID	C	G1	G2	G3	G4	G5	G6
	G7	G8	G9	-etc.-

Alternate Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
SPC1	SID	C	G1	"thru"	G2

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
SPC1	3	2	7	3	10	9	6	5
	THRU	8	33	71
SPC1	2	2	87	“thru”	100

Field	Contents
SID	Single-point constraint set identification number. (Integer > 0)
C	Component number. (Integer zero or blank for scalar points, or up to six unique digits (0 < digit < 6) may be placed in the field with no embedded blanks for grid points. The components refer to the coordinate system referenced by the grid points.)
Gi	Grid or scalar point identification numbers. (Integer > 0)

Comments

1.	The degree-of-freedom declared dependent on this entry may not be:

•	Included in another single-point constraint (SPC or SPC1)

•	Declared a dependent degree-of-freedom on any RBAR, RBE1, RBE2, or RROD entry

•	Declared a dependent degree-of-freedom on an MPC set referenced in the same subcase

2.	Note that enforced displacements are not available via this entry.

3.	Any number of continuations may appear.

4.	Multiple “thru” sequences can be used on a single card, and can span across continuation lines.

5.	SPC degrees-of-freedom may be redundantly specified as permanent constraints on the GRID entry.

6.	If the "thru" comment is used, G1 and G2 must exist, but the grid points between G1 and G2 are not required to exist.

For static and dynamic analyses, when the SPSYNTAX setting on the SYSSETTING I/O option is set to CHECK (default) or MIXED, it is allowed that when grid lists are provided for a given component, that the grid references be either scalar points (SPOINT) or structural grid points (GRID) when the component is 0, 1 or blank; interpreting all of these as 0 for scalar points and as 1 for structural grids. When SPSYNTAX is set to STRICT, it is required for grid/component pairs (G#/C#) that the component be 0 or blank when the grid references are to scalar points (SPOINT), and that the component be > 1 when the grid references are to structural grid points (GRID). When the component is greater than 1, the grid references must always be a structural grid (GRID).

For linear steady-state heat transfer analysis, SPC1 may be used to define temperature boundary conditions; however, unless paired with an SPCD entry, the enforced temperature is 0.0. For thermal boundary conditions, the component should be 0 or blank when the SPSYNTAX setting on the SYSSETTING I/O option is set to CHECK (default) or STRICT. When SPSYNTAX is set to MIXED, 1 is also accepted as the component.

9.	This card is represented as a constraint load in HyperMesh.