DVCON_SHAPE


ID_NAME	= `<name_of_dvcon_shape>`	Name of the `DVCON_SHAPE` definition.
ND_GROUP	= `<name_of_node_group>`	Name of the node group that is valid for the restriction. The node group should be a subset of the nodes of the `MESH_SMOOTH` command.
CHECK_BC	= YES = NO	Accepts (`YES`) or ignores (NO) the nodal fixations read by the FE interface as constraints on the selected node group.
CHECK_DOF	= `<cs_name>`, `<dof1>`,`<dof2>`,`<dof3>` (`<dof*>` = FIX, FREE)	The displacement in the corresponding coordinate direction in the referenced coordinate system is constrained (`FIX`) or allowed (FREE).
CHECK_ELGR	= `<name_of_element_group>`	Name of the element group that is checked for penetration.
CHECK_ELGR_BLOCKING	= BOTH \| POS \| NEG	Permeability for `CHECK_ELGR`. `BOTH`: (default) Element group is not penetrable from any side. Like current behavior with the known problems. `POS`: Element group is penetrable in negative normal direction and blocking in positive normal direction. `NEG`: Element group is penetrable in positive normal direction and blocking in negative normal direction.
CHECK_GROW	= `<grow_value>`	Maximum grow value (referring to the initial design). $(g r o w_\bar{v a l u e} \geq 0)$
CHECK_LINK	= `<link_shape_name>`	Assign a `LINK_SHAPE` definition.
CHECK_MAX_MEM	= `<radius>`	Maximum member size: orthogonal to the surface material of maximum 2*radius thickness must remain.
CHECK_MIN_MEM	= `<radius>`	Minimum member size: orthogonal to the surface material of minimum 2*radius thickness must remain.
CHECK_NDGR	= `<member_size_check_node_group>`	Name of surface node group for check of member size. If `CHECK_TYPE = TRANSITION`, then a link to a subset of the design area can be provided.
CHECK_SHRINK	= `<shrink_value>`	Maximum shrink value (referring to the initial design). $(s h r i n k_\bar{v a l u e} \geq 0)$
CHECK_SLIDE	= `<link_shape_name>`	Assign a slide surface defined with a `LINK_SHAPE` command.
CHECK_SOLID	= `<solid_name>`	Name of the solid that is checked for penetration.
CHECK_TYPE	= TRANSITION = FILTER	Create a transition area manufacturing constraint. Configure a (design variable) filter.
FEATURE_NODES	= <`node_group`>	Use external feature detection for `RESTRICT_ON_SURFACE`. The nodes in this group are considered to lie on an edge or on a corner.
FEASIBLE_START	= YES = NO	premise feasible node group (YES) or accept infeasible node group (`NO`) in the start model.
FUNCTION	= SMOOTH \| LINEAR	Control the form of the transition area for `CHECK_TYPE`= TRANSITION. SMOOTH: Transition area follows a sin curve. LINEAR: Transition area follows a linear slope.
REFERENCE_NDGR	= `<node_group>`	If `CHECK_TYPE = TRANSITION`, then this is a link to a node group describing the fixed edge.
RESTRICT_ON_SURFACE	= YES = NO	Restrict the nodes specified by `ND_GROUP` to move only tangential to their normal direction. This can be especially useful for variation areas - mesh smooth areas not part of the design area.
TOLERANCE	= `<tolerance_value>`	Tolerance value for member size check and CHECK_ELGR with CHECK_ELGR_BLOCKING set to POS or NEG. (absolute positive real value)
AGGREGATION_PARAMETER	= <`real`>	This is only evaluated for the demold manufacturing in sensitivity-based shape optimization. The parameter <`p`> should be > 1. Default value is `3`.
AGGREGATION_NUM_CONSTRAINTS	= <`integer`>	This is only evaluated for the demold manufacturing in sensitivity-based shape optimization. This parameter determines how many (optimization) constraints are created. Use `-1` to disable constraint aggregation. This results in the creation of as many constraints as possible - namely one constraint for each face in the group specified by ND_GROUP. Use `1` (default) to activate constraint aggregation.

Remarks

CHECK_BC:
- CHECK_BC=YES: The boundary conditions that are loaded with OPTIONS, READ_BC = ALL, are considered for the nodes of the node group.
- CHECK_BC=NO: The BC entries are not considered.
CHECK_DOF: Fixing the node coordinates named with FIX for the given coordinate system.
CHECK_ELGR (up to 6 operators with CHECK_ELGR are permitted) is the name of an element group already defined. All nodes in the node group (ND_GROUP) are checked for penetrating the element group. Shell and element groups are admitted.
CHECK_LINK: Identification name of a link condition (defined with LINK_SHAPE) which should be used for the node group.
CHECK_SOLID (up to 6 operators with CHECK_SOLID are permitted) is the name of a solid already defined (SOLID). All nodes are checked for penetrating the solid (restricted solid) and against leaving the solid area (variational solid), respectively.
When several CHECK_* entries are specified in a DVCON_SHAPE definition, they are used in the following sequence: CHECK_GROW / CHECK_SHRINK, CHECK_MAX_MEM, CHECK_MIN_MEM, CHECK_SOLID, CHECK_ELGR, CHECK_BC, CHECK_DOF, CHECK_LINK. If there are conflicts in the sequence of the CHECK_* entries, the last entry overwrites the previous one. If there are no conflicts in the sequence of the CHECK_* entries, all the defined restrictions are considered.
Apart from CHECK_SOLID and CHECK_ELGR entries (which can be used up to 6 times) only one entry of each other type is admitted in a DVCON_SHAPE definition. That means, for example, that I cannot combine two CHECK_LINK entries in one DVCON_SHAPE definition but must define two DVCON_SHAPE entries instead. On the other hand, one CHECK_LINK and CHECK_BC entry, for example, can be combined.
CHECK_TYPE = TRANSITION: For creating a transition area, the options ND_GROUP and REFERENCE_NDGR are mandatory. CHECK_NDGR is optional and is set to the shape design area if not specified.

Examples


DVCON_SHAPE
  ID_NAME      = my_dvcon_shape_01
  ND_GROUP     = nd_side_a
  CHECK_DOF    = csys1, FREE, FIX, FIX
END_

DVCON_SHAPE
  ID_NAME      = my_dvcon_shape_01
  ND_GROUP     = design_area
  CHECK_GROW   = 5.0
  CHECK_SHRINK = 5.0
END_