/DTPL

Optimization Keyword Defines parameters for the generation of topology design variables.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/DTPL/dtpl_ID
title
grpart_ID TMIN STRESS MEMBSIZ PATRN PATREP EXTR MESH DRAW MMOCID
TMIN =0/1, if TMIN=1, read thickness definition: T0
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
T0
STRESS=0/1, if STRESS=1, read stress constraint definition: MAXSTRS
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MAXSTRS
MEMBSIZ=0/1, if MEMBSIZ=1, read member size constraint definition:
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MINDIM MAXDIM MINGAP
PATRN=0/1, if PATRN=1, read pattern grouping constraint definition: 2
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
TYP AID XA YA ZA
FID XF YF ZF
UCYC SID XS YS ZS

PATREP=0/1/2,

If PATREP=1, read MAIN definitions for pattern repetition constrain:t 3
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
ptrepCID
CAID XCA YCA ZCA
CFID XCF YCF ZCF
CSID XCS YCS ZCS
CTID XCT YCT ZCT
If PATREP=2, read SECOND definitions for pattern repetition constraint: 3
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
mainID SX SY SZ
ptrepCID
CAID XCA YCA ZCA
CFID XCF YCF ZCF
CSID XCS YCS ZCS
CTID XCT YCT ZCT
EXTRU=0/1, if EXTRU=1, read the extrusion constraint definition: 4
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
ETYP extrGRN1 extrGRN2
MESH=0/1, if MESH=1, read mesh type definition:
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MTYP
DRAW=0/1, if DRAW=1, read draw direction constraint definition: 5
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DTYP DAID XDA YDA ZDA
DFID XDF YDF ZDF
ogrpart NOHOLE TSTAMP
MMOCID=0/1, if MMOCID=1, read skew identifier for mapping the design domains in Multi-Model Optimization:
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MCID

Definition

Field Contents SI Unit Example
dtpl_ID Topology design variable identifier.

(Integer > 0)
title Title.

(Character, maximum 100 characters)
grpart_ID Part group identifier defining the design space.

(Integer > 0)
TMIN Indicates if minimum thickness definition is defined.
= 0 (Default)
No
= 1
Yes

(Integer)
T0 Minimum thickness.

(Real > 0.0)
STRESS Indicates if the von Mises stress constraint is to be defined.
= 0
No
= 1
Yes

(Integer)
MAXSTRS Upper bound of the constraint on von Mises stress.

No default (Real > 0.0)
MEMBSIZ Active Member Size Control flag.
= 0
No
= 1
Yes

(Integer ≥ 0)
MINDIM Specifies the minimum diameter of members formed. This field can be used to eliminate small members. It also eliminates checkerboard results.

Default = No Minimum Member Size Control (Real > 0.0)
MAXDIM Specifies the maximum diameter of members formed. This field can be used to prevent the formation of large members. It can only be used in conjunction with MINDIM.

Default = No Maximum Member Size Control (Real > 0.0)
MINGAP Defines the minimum spacing between structural members formed. This command can only be used in conjunction with MAXDIM.

Default = blank (Real > MAXDIM)
PATRN Active pattern grouping flag. 1
= 0
No
= 1
Yes

(Integer)
TYP Pattern grouping type requested.
= 1
1-plane symmetry
= 2
2-plane symmetry
= 3
3-plane symmetry
= 10
Cyclic
= 11
Cyclic with symmetry

Default = No pattern grouping (Integer)
AID Anchor node identifier for variable pattern grouping definition.
blank
The XA, YA, and ZA fields should not be blank.

(Integer > 0 or blank)
XA, YA, ZA Coordinates of the pattern grouping anchor point.
blank
AID should not be blank.

(Real or blank)
FID Node identifier used to define the direction of the first vector for variable pattern grouping.
blank
The XF, YF, and ZF fields should not be blank.

(Integer > 0 or blank)
XF, YF, ZF Components of the first vector used to define pattern grouping.
blank
FID should not be blank.

(Real or blank)
UCYC Number of cyclic repetitions for cyclical symmetry. This field defines the number of radial "wedges" for cyclical symmetry. The angle of each wedge is computed as 360.0/UCYC.

Default = blank (Integer > 0 or blank)
SID Node identifier of the second point for pattern grouping definition.
blank
The XS, YS, and ZS fields should not be blank.

(Integer or blank)
XS, YS, ZS Coordinates of the second point for pattern grouping definition.
blank
SID should not be blank.

(Real or blank)
PATREP Indicates whether pattern repetition is defined and the type of pattern repetition. 2
= 0
No pattern repetition.
= 1
Pattern repetition is defined, and this design variable is main.
= 2
Pattern repetition is defined, and this design variable is secondary.

(Integer)
mainID Main /DTPL identifier for pattern definition.

(Integer > 0) Only needed if PATREP =2.
SX, SY, SZ Scale factors for pattern repetition in X, Y, and Z directions, respectively.

Default = 1.0 (Real > 0.0)
ptrepCID Skew coordinate system identifier that defines the pattern repetition coordinate system.

Default = 0 (Integer ≥ 0)
CAID Node identifier of the anchor point for the definition of a pattern repetition coordinate system.
blank
The XCA, YCA, and ZCA fields should not be blank.

(Integer > 0 or blank)
XCA, YCA, ZCA Coordinates of anchor point for the definition of a pattern repetition coordinate system.
blank
CAID should not be blank.

(Real or blank)
CFID Node identifier of the first point for the definition of a pattern repetition coordinate system.
blank
The XCF, YCF, and ZCF fields should not be blank.

(Integer > 0 or blank)
XCF, YCF, ZCF Coordinates of the first point for the definition of a pattern repetition coordinate system definition.
blank
CFID should not be blank.

(Real or blank)
CSID Node identifier of the second point for the definition of a pattern repetition coordinate system.
blank
The XCS, YCS, and ZCS fields should not be blank.

(Integer > 0 or blank)
XCS, YCS, ZCS Coordinates of the second point for the definition of a pattern repetition coordinate system.
blank
CSID should not be blank.

(Real or blank)
CTID Node identifier of the third point for the definition of a pattern repetition coordinate system.
blank
The XCT, YCT, and ZCT fields should not be blank.

(Integer > 0 or blank)
XCT, YCT, ZCT Coordinates of the third point for the definition of a pattern repetition coordinate system.
blank
CTID should not be blank.

(Real or blank)
EXTRU Active extrusion constraint flag. 3
= 0
Not active
= 1
Active

(Integer)
ETYP Extrusion constraint type to be used.
= 0
NOTWIST.
Indicates that the cross-section cannot twist around the neutral axis, in which case only one path needs to be defined.
= 1
TWIST.
Indicates that the cross-section can twist around the neutral axis, in which case two paths need to be defined.

(Integer)
extrGRN1 Node group identifier that defines the primary extrusion path.

(Integer > 0)
extrGRN2 Node group identifier that defines the secondary extrusion path.

If this field is blank, the secondary extrusion path is not specified.

(Integer > 0 or blank)

This is only required when ETYP=1 (TWIST) is defined.
MESH Indicates that mesh type information is to follow.
= 0
Not active
= 1
Active

(Integer)
MTYP Indicates that the mesh conforms to certain rules for which the optimizer is tuned. Currently, only the ALIGN option is available.
= 1
ALIGN
Indicates when manufacturing constraints are active, the mesh is aligned with the draw direction or extrusion path.

(Integer)
DRAW Active draw/casting direction constraint flag. 4
= 0
Not active
= 1
Active

(Integer)
MMOCID Skew identifier flag for mapping the design domains in Multi-Model Optimization.
= 0
Not active
= 1
Active
DTYP Draw direction constraint type to be used.
= 1
Single die

(Integer)
DAID Node identifier used for the definition of a draw direction anchor point.
blank
The XDA, YDA, and ZDA fields should not be blank.

(Integer > 0 or blank)
XDA, YDA, ZDA Coordinates of the draw direction anchor point.

If XDA, YDA, and ZDA are blank, DAID should not be blank.

(Real or blank)
DFID Node identifier for the definition of a draw direction point. The vector is defined from the anchor point to this point.
blank
The XDF, YDF, and ZDF fields should not be blank.

(Integer > 0 or blank)
XDF, YDF, ZDF Direction of the vector for draw direction definition. These fields define a point. The vector is defined from the anchor point to this point.

If XDF, YDF, and ZDF are blanks, DFID should not be blank.

(Real or blank)
ogrpart Part group identifier of non-designable parts, whose interaction with designable parts needs to be considered with regard to the defined draw direction. OBST stands for obstacle.
Only recognized if DRAW flag is also present on same DTPL card.
> 0
Part group identifier of non-designable parts.
blank
This definition is not active.

(Integer)
NOHOLD Flag preventing the formation of through-holes in the draw direction.
Note: It does not prevent holes perpendicular to the draw direction. The assumed minimum thickness in the draw direction is twice the average mesh size.
= 0
Control off
= 1
Control on

(Integer)
TSTAMP Defines the thickness of the 3D shell structure into which the design is forced to evolve into. The recommended minimum thickness is three times the average mesh size.
blank
The design is not forced to evolve into a 3D shell structure.

(Real > 0.0 or blank)
MCID Skew identifier used for mapping the design domains in Multi-Model Optimization.

Example

Pattern is activated with TYP=1 (1-plane symmetry)
Figure 1. Pattern is activated and use TYP=1 (1-plane symmetry)

dtpl_example
/DTPL/1
grpart 6 for topology optimization
### PATRN=1: active pattern
### TYP= 1: 1-plane symmetry
### AID=1: anchor node ID for variable pattern is 1
### FID=17: Node ID 17 used to define the direction of the first vector
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#grpart_ID      TMIN    STRESS   MEMBSIZ     PATRN    PATREP      EXTR      MESH      DRAW
         6                                       1
#      TYP       AID                  XA                  YA                  ZA
         1         1
#                FID                  XF                  YF                  ZF
                  17
#     UCYC       SID                  XS                  YS                  ZS
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Example (MMODIC)

Draw and MMOCID is activated with TYP=1 (1-plane symmetry).
Figure 2.

dtpl_example_mmocid
Figure 3.

dtpl_example_mmo_topo
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/DTPL/1
grpart 1 for topology optimization
### MEMBSIZ=1: active member size control
### DRAW=1: active draw/casting direction constraint
### MMOCID=1: active Skew identifier flag for mapping the design domains in Multi-Model Optimization
### minimum diameter of members MINDIM=40 and maximum diameter of members MAXDIM=80
### TYP= 1: 1-plane symmetry
### Normal vector is from Anchor node (XA,YA,ZA) to First node (XF,YF,ZF)
### MCID=1: Skew identifier 1 used for mapping the design domains in Multi-Model Optimization
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#grpart_ID      TMIN    STRESS   MEMBSIZ     PATRN    PATREP      EXTR      MESH      DRAW    MMOCID
         1                             1                                                 1         1
#             MINDIM              MAXDIM               MINGAP
                  40                  80
#      TYP       AID                  XA                  YA                  ZA
         1                             0                   0                   0
#                FID                  XF                  YF                  ZF
                                       0                   0                  -1
#     UCYC       SID                  XS                  YS
#     MCID
         1
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

  1. For PATRN=1 (active pattern), there are five pattern grouping options.
    This type of pattern grouping requires the anchor point and first point to be defined. A vector from the anchor point to the first point is normal to the plane of symmetry.
    Figure 4. 1-plane symmetry (TYP = 1)

    dtpl_1_plane
    This type of pattern grouping requires the anchor point, first point, and second point to be defined. A vector from the anchor point to the first point is normal to the first plane of symmetry. The second point is projected normally onto the first plane of symmetry. A vector from the anchor point to this projected point is normal to the second plane of symmetry.
    Figure 5. 2-plane symmetry (TYP = 2)


    This type of pattern grouping requires the anchor point, first point, and second point to be defined. A vector from the anchor point to the first point is normal to the first plane of symmetry. The second point is projected normally onto the first plane of symmetry. A vector from the anchor point to this projected point is normal to the second plane of symmetry. The third plane of symmetry is orthogonal to both the first and second planes of symmetry, passing through the anchor point.
    Figure 6. 3-plane symmetry (TYP = 3)

    dtpl_3_plane
    This type of pattern grouping requires the anchor point, first point, and number of cyclical repetitions to be defined. A vector from the anchor point to the first point defines the axis of symmetry.
    Figure 7. Cyclic (TYP = 10)

    dtpl_cyclic_10
    This type of pattern grouping requires the anchor point, first point, second point, and number of cyclical repetitions to be defined. A vector from the anchor point to the first point defines the axis of symmetry. The anchor point, first point, and second point all lay on a plane of symmetry. A plane of symmetry lies at the center of each cyclical repetition.
    Figure 8. Cyclic with symmetry (TYP = 11)

    dtpl_cyclic

    For a more detailed description, refer to Pattern Grouping contained within the Topology Optimization Manufacturability section of the User Guide.

  2. PATREP =1, read MAIN definitions for pattern repetition constraint.

    PATREP =2, read SECOND definitions for pattern repetition constraint.

    For a more detailed description, refer to Pattern Repetition.

  3. EXTRU =1, read the extrusion constraint definition. There are two types of extrusion constraints: ETYP=0 (non-twisted cross-section) and ETYP =1 (twisted cross-section).
    Figure 9.

    dtpl_extru

    For a more detailed description, refer to Extrusion Constraints.

  4. DRAW =1, read draw direction constraint definition. The type of draw direction that could be used is single die (DTYP =1).
    Figure 10.

    dtpl_draw

    For a more detailed description, refer to Draw Direction Constraints.

  5. This entry is represented as an optimization design variable in HyperMesh.