STOP

Definition of STOP conditions.

This page discusses:

See Also
In Other Guides
Global Stop Criterion (Number of Iterations)
Convergence Criteria
Global Stop Condition (Number of Iterations)

ID_NAME

= <id_name_of_stop_condition>

Name of the STOP condition.

LOGICAL

= <name_of_logical_variable>

Name of a logical variable.

ITER_MAX

= <value>

= 50 (size/topo sens)

= 50 (shape controller/sens)

= 15 (topo controller)

= 20 (bead sens)

= 3 (bead controller)

Maximum number of iterations. For topology and sizing sens, the default value will be 80 iterations when nonlinear material or stress dresps are present in the optimization

The following parameters are available only in combination as Logical Condition:

MOD_NDGR

= <name_of_node_group>

Node group for which the comparison is made.

MOD_TYPE

<mod_type_1>, <mod_type_2>

The parameter <mod_type_1> of the variable specified in the second parameter <mod_type_2> is compared to MOD_REF using the operator specified in MOD_OPER.

<mod_type_1>

= MAX

= MIN

= SUM

= COUNT

<mod_type_2>

= MOVE

Amount of optimization displacement.

= MOVE_GROWTH

Like MOVE, but only positive.

= MOVE_SHRINK

Like MOVE, but only negative.

= MOVE_TOTAL

Optimization displacement referring to initial model.

= MOVE_GROWTH_TOTAL

Like MOVE_TOTAL, but only positive.

= MOVE_SHRINK_TOTAL

Like MOVE_TOTAL, but only negative.

= CTRL_INP

Controller input value (equivalent stress).

= CTRL_INP_SHAPE

CTRL_INP of design nodes.

= CTRL_INP_SHAPE_FIX

CTRL_INP of restricted design nodes.

= CTRL_INP_SHAPE_FREE

CTRL_INP of free design nodes.

= CTRL_INP_SURFACE

CTRL_INP of surface nodes.

MOD_OPER

Comparison operator.

=LT

Less than.

= LE

Less or equal.

= EQ

Equal.

= GE

Greater or equal.

= GT

Greater than.

MOD_REF

= <real>, <mod_ref_1>, <mod_ref_2>

The real value is linked with the <mod_ref_2> specified iteration in the way described by <mod_ref_1>.

<mod_ref_1>

= MULT

Multiplication.

= ADD

Sum.

= SUB

Subtraction

= DIV

Division.

<mod_ref_2>

= PREV

Previous (iteration).

= FIRST

First (iteration).

OPTIMIZE

= <name_of_optimization>

Name of the optimization task.

Remarks

  1. Using the parameter ITER_MAX a global stop condition can be set. In the optimization system, a number of 40 iterations is set by default.
  2. If a global STOP condition is defined, no other parameters can be defined in the STOP command. If an additional logical STOP condition must be defined, another STOP definition must be defined.

Examples

The optimization should stop, when the maximum equivalent stress of the node group all_nodes is smaller than 1% of the maximum equivalent stress of the first iteration:


STOP
 ID_NAME  = stop_command
 MOD_NDGR = ALL_NODES
 MOD_TYPE = MAX, CTRL_INP_SHAPE
 MOD_OPER = LE
 MOD_REF  = 0.01, MULT, FIRST
 OPTIMIZE = run
END_

The optimization should stop when the equivalent maximum von Mises stress in the design area is smaller than 200 MPa.


VARIABLE
 ID_NAME    = var_sig
 DEF_TYPE   = SYSTEM
 TYPE       = SIG_MISES
 ND_GROUP   = design_nodes
 GROUP_OPER = MAX
END_

LOGICAL
 ID_NAME  = logi_1
 DEF_TYPE = BASE
 OPER     = LT
 VAR_A    = var_sig
 FIX_VAL  = 200
END_

STOP
 ID_NAME = my_stop_condition
 LOGICAL = logi_1
 OPTIMIZE = my_optimization_problem
END_