DMIGMOD

Bulk Data Entry

DMIGMOD – H3DDMIG Modification

Description

Defines changes in the contents of a super element from H3DDMIG input.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
DMIGMOD	MTXNAME	SHFGID	SHFSPID	SHFSPID_F	SHFCID	SHFEID	SHFRID
	HYBDAMP	METHOD	SDAMP	KDAMP	METHOD_F	SDAMP_F	KDAMP_F
	ORIGIN	A1	A2	A3
	GIDMAP	GID1	GID1A	GID2	GID2A	GID3	GID3A
	CIDMAP	CID1	CID1A	CID2	CID2A	CID3	CID3A
	RELOC	PA1	PA2	PA3	PB1	PB2	PB3
	GRDTOL	ERREXT	TOLEXT	ERRINT	TOLINT

Field	Contents
MTXNAME	Matrix name defined on ASSIGN,H3DDMIG. No default (1 to 6 characters)
SHFGID	All Grid identification numbers in the superelement are shifted by the specified value. If this field is left blank, then a shift does not occur (Comment 2). Default = blank (Integer or blank)
SHFSPID	All SPOINT identification numbers in the superelement are shifted by the specified value. If this field is left blank, then a shift does not occur (Comment 2). Default = blank (Integer or blank)
SHFSPID_F	All Fluid SPOINT identification numbers in the superelement are shifted by the specified value. If this field is left blank, then a shift does not occur (Comment 2). Default = blank (Integer or blank)
SHFCID	All Coordinate System identification numbers in the superelement are shifted by the specified value. If this field is left blank, then a shift does not occur (Comment 2). Default = blank (Integer or blank)
SHFEID	All Element identification numbers in the superelement are shifted by the specified value. If this field is left blank, then a shift does not occur (Comment 2). Default = blank (Integer or blank)
SHFRID	All Rigid Element identification numbers in the superelement are shifted by the specified value. If this field is left blank, then a shift does not occur (Comment 2). Default = blank (Integer or blank)
HYBDAMP	Keyword for the remaining data for superelement damping.
METHOD	EIGRL card identification number. Hybrid damping would be applied on the superelements for the modes referred by EIGRL card. If blank, then applied damping on all the modes. Default = blank (Integer > 0, or blank)
SDAMP	Identification number of TABDMP1 entry for modal damping. No default (Integer > 0)
KDAMP	If set to -1, viscous modal damping is entered into the complex stiffness matrix as structural damping instead of viscous damping. Default = 1 (Integer)
METHOD_F	EIGRL card identification number. Hybrid damping would be applied on the fluid part of superelement for the modes referred by the EIGRL card. If blank, then modal damping is applied damping to all the fluid modes.
SDAMP_F	Identification number of TABDMP1 entry for fluid modal damping of the superelement. No default (Integer > 0)
KDAMP_F	If set to -1, viscous modal damping is entered into the complex stiffness matrix as structural damping instead of viscous damping. Default = 1 (Integer)
ORIGIN	Keyword for defining the new ORIGIN for DMIG.
A1,A2,A3	Defines the new location of the origin of the DMIG. Default = 0.0 (Real)
GIDMAP	Keyword for defining mapped grid ID pairs.
GIDn,GIDnA	Mapped grid ID pairs.
CIDMAP	Keyword for defining mapped coordinate system ID pairs.
CIDn,CIDnA	Mapped coordinate system ID pairs.
RELOC	Keyword indicating that matching grid point ID pairs in the residual structure and superelement are to follow (Comment 1).
PA1, PA2, PA3	ID’s of three non-collinear grid points in the residual structure.
PB1, PB2, PB3	ID’s of three non-collinear grid points in the superelement that will be matched to corresponding grid points in the residual structure (defined by PA1, PA2 and PA3).
GRDTOL	Indicates that the grid point tolerance settings between matching residual and superelement grids are to follow.
ERREXT	Specifies whether OptiStruct errors out (ERROR) or outputs a warning (WARN) for inconsistent exterior grid locations based on a defined tolerance value (TOLEXT). Default = ERROR (ERROR or WARN)
TOLEXT	Tolerance value to compare exterior grid locations. Default = 1.0e-15
ERRINT	Specifies whether OptiStruct errors out (ERROR) or outputs a warning (WARN) for inconsistent interior grid locations based on a defined tolerance value (TOLINT). Default = ERROR (ERROR or WARN)
TOLINT	Tolerance value to compare interior grid locations. Default = 1.0e-5

Comments

The RELOC entry and its related fields define three matching grid point pairs on the residual structure and the superelement. The superelement defined using ASSIGN, H3DDMIG is relocated (translated and rotated, as required) such that the three non-collinear grids PB1, PB2, and PB3 coincide with PA1, PA2, and PA3, respectively on the residual structure.

dmigmod

Figure 1: Matching three grids on the superelement with grids on the residual structure

Identification numbers of certain entities in a superelement can be modified during H3DDMIG input. Negative integers can be input in the shift fields on this entry (see fields beginning with ‘SHF’ above), however, care should be taken to ensure that the identification numbers are not shifted to negative values. The values of identification numbers after shifting should always be greater than zero, otherwise, the run will error out.

The use-case of GIDMAP is to renumber the interface grids IDs such that they match with the IDs used in the residual structure. Also, renumbering interior grids IDs such that they do not conflict with exterior grids or with interior grids in another superelement. For the latter use-case, SHFGID will also be used to avoid the conflict. If both GIDMAP and SHFGID are used together for the same superelement, the renumbered grids with GIDMAP will not be renumbered again by SHFGID.