Optimizing the Shaft Model

Define input data, additional groups, and design variables.

FEM_INPUT
  ID_NAME        = MY_INPUT_FILES
  FILE           = shaft_surfturn_sens.inp
END_

include, shaft_surfturn_sens.inc

GROUP_DEF
  ID_NAME        = NODES_FOR_DISP
  TYPE           = NODE
  FORMAT         = LIST
  LIST_BEGIN
  13, 440
END_

DV_SHAPE
  ID_NAME        = MY_DV_SHAPE
  ND_GROUP       = design_nodes
END_

Create geometrical constraints.

Rotational Symmetry (SURF_TURN):

LINK_SHAPE
  ID_NAME        = LS_TURN
  CLIENT         = SURF_TURN
  MAIN         = AUTO
  CLIENT_DIR     = 0, 1, 0
  CS             = CS_0
END_

DVCON_SHAPE
  ID_NAME        = DVCON_SHAPE_SURF_TURN
  CHECK_BC       = NO
  ND_GROUP       = design_nodes
  CHECK_LINK     = LS_TURN
END_

Node fixations:

CS_DEF
  ID_NAME        = MY_CS
  DEF_TYPE       = LOCAL
  CS_TYPE        = CYLINDRICAL
  CS_REF         = CS_0
  ORIGIN_123     = 0, 0, 0
  ROTATION_321   = 0, 0, 270
END_

DVCON_SHAPE
  ID_NAME        = DVCON_SHAPE_FIXED
  CHECK_BC       = NO
  ND_GROUP       = nodes_fixed
  CHECK_DOF      = MY_CS, FIX , FREE, FREE
END_

Shrink control:

DVCON_SHAPE
  ID_NAME        = SHRINK_CTRL
  CHECK_SHRINK   = 3.
  ND_GROUP       = design_nodes
END_

Create a constraint for the volume.

Define a Design Response with the volume (DRESP):

DRESP
 ID_NAME    = DRESP_VOLUME
 LIST       = NO_LIST
 DEF_TYPE   = SYSTEM
 EL_GROUP   = ALL_ELEMENTS
 TYPE       = VOLUME
 UPDATE     = EVER
 GROUP_OPER = Sum
END_

Reference the Design Response in a constraint (CONSTRAINT) and constrain it to 100%.

CONSTRAINT
 ID_NAME   = VOLUME_CONSTRAINT
 DRESP     = DRESP_VOLUME
 MAGNITUDE = REL
 LE_VALUE  = 1.0
END_

To define the Objective Function (OBJ_FUNC) for the plastic equivalent magnitude (PEMAG) in the second load case, do the following:
1. Create a Design Response (DRESP).
```
DRESP
 ID_NAME  = DRESP_PEMAG
 DEF_TYPE = SYSTEM
 TYPE     = PEMAG
 EL_GROUP = ALL_ELEMENTS
END_
```
2. Define the objective function.
```
OBJ_FUNC
 ID_NAME = OBJ_FUNCTION
 TARGET  = MIN
 DRESP   = DRESP_PEMAG
END_
```

Design responses and optimization functions

DRESP
  ID_NAME    = VOLUME
  DEF_TYPE   = SYSTEM
  TYPE       = VOLUME
  EL_GROUP   = ALL_ELEMENTS
END_

DRESP
  ID_NAME    = DISPLACEMENT_X
  DEF_TYPE   = SYSTEM
  TYPE       = DISP_X_ABS
  ND_GROUP   = NODES_FOR_DISP
  GROUP_OPER = Max
  CS_REF     = CS_0
END_

DRESP
  ID_NAME    = DISPLACEMENT_Z
  DEF_TYPE   = SYSTEM
  TYPE       = DISP_Z_ABS
  ND_GROUP   = NODES_FOR_DISP
  GROUP_OPER = Max
  CS_REF     = CS_0
END_

OBJ_FUNC
  ID_NAME    = MY_OBJ_FUNC
  TARGET     = MINMAX
  DRESP      = DISPLACEMENT_X, ,
  DRESP      = DISPLACEMENT_Z, ,
END_

CONSTRAINT
  ID_NAME    = VOLUME_CONSTRAINT
  MAGNITUDE  = REL
  DRESP      = VOLUME
  LE_VALUE   = 1.0
END_

Mesh regularization

MESH_SMOOTH
  ID_NAME             = MY_MESH_SMOOTH
  CORRECT_ELEMENTS    = YES
  FREE_SF             = FREE
  MS_LAYER            = design_nodes, 4
  FREEZE_DESIGN_NODES = YES
END_

Reference the Design Variables, Objective Function, and Constraints as well as DVCONs in the OPTIMIZE command.

OPTIMIZE
  ID_NAME        = MY_OPTIMIZATION_TASK
  OBJ_FUNC       = MY_OBJ_FUNC
  DV             = MY_DV_SHAPE
  CONSTRAINT     = VOLUME_CONSTRAINT
  STRATEGY       = SHAPE_SENSITIVITY
  DVCON          = DVCON_SHAPE_SURF_TURN
  DVCON          = DVCON_SHAPE_FIXED
  DVCON          = SHRINK_CTRL
  MESH_SMOOTH    = MY_MESH_SMOOTH
END_

Set stop condition.

STOP
  ID_NAME        = MY_STOP
  ITER_MAX       = 150
END_

The optimization result looks as follows: