DMIG

Bulk Data Entry Defines direct input matrices related to grid points. The matrix is defined by a single header entry and one or more column entries. A column entry is required for each column with non-zero elements.

The DMIG entry can be used to define matrices to be included in the model, such as stiffness matrices, mass matrices, and so on. DMIG entries can be selected in the case control section using K2GG, K42GG, M2GG, B2GG, and so on for inclusion in the model. The input matrix must be symmetric (IFO = 6) for K2GG, K42GG, M2GG, B2GG entries. K2PP, M2PP, and B2PP are supported with IFO values of 1, 6 and 9.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMIG NAME "0" IFO TIN       NCOL  

Column Entry Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMIG NAME GJ CJ   G1 C1 A1 B1  
  G2 C2 A2 B2 G3 etc etc    

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMIG STIF 0 9         2  
DMIG STIF 27 1   120 3 3.+5    
  120 4 2.5+10            
DMIG STIF 28 1   123 3 6.+7    
  123 4 4.1+8            

Definitions

Field Contents SI Unit Example
NAME Name of the matrix. Matrices may be selected for all solution sequences by the structural matrices before constraints are applied.

No default (One to eight alphanumeric characters, the first must be alphabetic)

  
"0" The field should always be set to the integer "0".  
IFO Form of matrix input.
1
Square matrix
6
Symmetric matrix
9
Rectangular matrix

No default (Integer)

  
TIN Matrix input type.
1
Single precision real.
2
Double precision real.
3
Single precision complex.
4
Double precision complex.

No default (Real)

  
NCOL Number of columns in a rectangular matrix. Must be used when IFO = 9. Not used when IFO = 6.

Default = blank (Integer > 0, or blank)

  
GJ Grid point identification number for column index.

No default (Integer > 0)

  
CJ The component number for grid point GJ.

No default (0 < Integer ≤ 6)

  
Gi Grid point identification number for row index.

No default (Integer > 0)

  
Ci The component number for Gi for a grid point.

No default (0 < CJ ≤ 6)

  
Ai The real value of a matrix element.

No default (Real)

  
Bi Imaginary value of a matrix element.

No default (Real)

  

Comments

  1. The header entry containing IFO is required. Each no-null column is started with a GJ, CJ pair. The entries for each row of that column follow. Only non-zero terms need to be entered. The terms may be input in arbitrary order. A GJ, CJ pair may be entered more than once, but input of an element of the matrix more than once will produce a fatal message.
  2. Field 3 of the header entry must contain the integer "0".
  3. When IFO=6, a given off-diagonal element may be input either below or above the diagonal. While upper and lower triangle terms may be mixed, a fatal message will be issued if an element is input both below and above the diagonal.
  4. The matrix names must be unique among all DMIGs.
  5. The recommended format for rectangular matrices requires the use of NCOL and IFO = 9. The number of columns in the matrix is NCOL. (The number of rows in all DMIG matrices is always g-set size). The GJ term is used for the column index. The CJ term is ignored.
  6. When the SPSYNTAX setting on the SYSSETTING I/O Option is set to CHECK (default) or STRICT, it is required for grid/component pairs (G#/C#) that the component be 0 or blank when the grid reference is a scalar point (SPOINT), and that the component be ≥ 1 when the grid reference is a structural grid point (GRID). When SPSYNTAX is set to MIXED, it is allowed for grid/component pairs (G#/C#) that the grid reference be either a scalar point (SPOINT) or a structural grid point (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 the component is greater than 1, the grid reference must always be a structural grid (GRID).
  7. The DMIG matrices can be multiplied by real numbers and combined when referenced by the K2GG, M2GG, K42GG, K2PP, B2GG, and A2GG data.
  8. DMIG CDSHUT is a special case of DMIG usage for MPC-based Fast Contact Analysis. Therefore, it is recommended to avoid using the name "CDSHUT" for any DMIG's that are included for any other solution sequences.
  9. DMIG matrices can be referenced in Large Displacement Nonlinear Static and Transient analyses using DMIGROT. They can only be referenced by K2GG or P2G.
  10. Hash-table based assembly must be specified via PARAM,HASHASSM,YES for large displacement nonlinear analysis with DMIG matrices referenced by K2GG.