Rib Design Definition
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Using the graphical user interface choose Command > DVCON_TOPO in
Tosca Structure.pre
and define the rib restriction with the available fields shown in the following figure:
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Or use the
DVCON_TOPO
command:DVCON_TOPO ID_NAME = <Name of DVCON object> EL_GROUP = <Element group to be restricted> CHECK_TYPE = RIB_DESIGN CHECK_GROUP = <Element group to be checked for restriction> RIB_THICKNESS = <Averaged thickness of ribs> RIB_DISTANCE = <Averaged distance of rib centers> RIB_DIRECTION = <X_COMP>, <Y_COMP>, <Z_COMP> RIB_CS = <Name of coordinate system> APPROXIMATE = YES | NO, optional: <scale factor> END_
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A rib restriction is activated by setting the
CHECK_TYPE
of the design variable constraint toRIB_DESIGN
. The restriction definition contains the following parameters:-
ELEMENT_GROUP
: The group of elements for which the constraint is active. Defining an element group is mandatory. -
CHECK_GROUP
: The group of elements that are checked if elements are properly supported and do not violate the rib restriction. Most often it is best to use the same group as inELEMENT_GROUP
. All elements are used if this parameter is empty. -
RIB_THICKNESS
: The averaged thickness of the ribs. -
RIB_DISTANCE
: The averaged distance between the rib centers. The distance must be larger than twice the average element edge length. -
RIB_DIRECTION
: Out-of-plane growth direction of the ribs. -
RIB_CS
: Coordinate system for the definition of the rib direction. -
APPROXIMATE
: Option to turn on or turn off an approximating, but more performant algorithm. The scale factor defines how coarse the evaluation of the constraint is.Important: - It is only required to define an additional volume/mass constraint for the
design area when its constraint value is below
RIB_THICKNESS
/ 2*RIB_DISTANCE
. In addition, the recommendation is to use nonfrozen design elements only in theELEMENT_GROUP
.
- It is only required to define an additional volume/mass constraint for the
design area when its constraint value is below
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