Maximizing the Stiffness of the Rib Oil Pan Example

This example shows the usage of the rib pattern restriction with an oil pan model.

See Also
About Checking the Quality of the Optimization Result
  1. Define input data and Design Variables: 
    FEM_INPUT
  ID_NAME  = INPUT_FILE
  FILE     = topo_ribs_oilpan.inp
END_

DV_TOPO
  ID_NAME  = DESIGN_AREA
  EL_GROUP = ALL_ELEMENTS
END_
  2. Define additional groups for frozen elements: 
    GROUP_DEF
  ID_NAME = FROZEN
  TYPE    = ELEM
  FORMAT  = LIST
  LIST_BEGIN
87593, ...
END_

GROUP_DEF
  ID_NAME = NON_FROZEN
  TYPE    = ELEM
  FORMAT  = LIST_SUBTRACT_GROUP
  LIST_BEGIN
ALL_ELEMENTS, frozen
END_
  3. To use the compliance in the objective, define a Design Response (DRESP) as follows: 
    DRESP
  ID_NAME       = COMPLIANCE_TERM_1
  DEF_TYPE      = SYSTEM
  TYPE          = STRAIN_ENERGY
  EL_GROUP      = ALL_ELEMENTS
  UPDATE        = EVER
  GROUP_OPER    = SUM
END_
  4. Define the Objective Function (OBJ_FUNC) as follows: 
    OBJ_FUNC
  ID_NAME       = COMPLIANCE_OBJ
  DRESP         = COMPLIANCE_TERM_1
  TARGET        = MIN
END_
  5. Define the rib pattern and frozen DVCONs: 
    DVCON_TOPO
  ID_NAME       = FROZEN_AREA
  CHECK_TYPE    = FROZEN
  EL_GROUP      = FROZEN
END_

DVCON_TOPO
  ID_NAME       = DVCON_RIBS
  CHECK_TYPE    = RIB_DESIGN
  EL_GROUP      = NON_FROZEN
  CHECK_GROUP   = NON_FROZEN
  RIB_THICKNESS = 4
  RIB_DISTANCE  = 5
  RIB_DIRECTION = 0., 0., 1.
END_
  6. Reference the Objective Function, Design Variables and Constraint as well as DVCON in the OPTIMIZE command: 
    OPTIMIZE
  ID_NAME       = OPTIMIZE_1
  DV            = DESIGN_AREA
  OBJ_FUNC      = COMPLIANCE_OBJ
  DVCON         = FROZEN_AREA
  DVCON         = DVCON_RIBS
  STRATEGY      = TOPO_SENSITIVITY
END_
  7. Set the maximum number of iterations to 100 
    STOP
  ID_NAME  = GLOBAL_STOP_CONDITION
  ITER_MAX = 100
END_

The optimization result looks as follows: