LINK_SHAPE

Special Items for CLIENT Parameters

Not all entries are allowed for each parameter as shown in the following table:

Remarks

1. The allocation is only permitted for design nodes (defined by the command DV_SHAPE) and mesh smooth nodes (second order design nodes).
2. The MAIN specification determines the main nodes.

   	Case 1	Case 2	Case 3	Case 4
   	ALL_GROWTH	ALL_SHRINK	MORE_SHRINK	MORE_GROWTH
   MAIN	Selected Main Displacement Value
   MAX	max_growth	min_shrink	max_growth	max_growth
   MIN	min_growth	max_shrink	max_shrink	max_shrink

3. The CLIENT specification determines the displacement of the client nodes from the main_Node of the optimization displacement.
   1. CLIENT = PLANE_SYM: The surface that lies normal to the specified axis is a symmetrical surface. The nodes (allocated by DVCON_SHAPE operator ND_GROUP) are checked against each other for their symmetry and symmetrical surfaces. Symmetrical nodes are combined to a symmetrical group (2 symmetrical nodes per symmetrical group is the norm). The main node of the symmetrical group is then determined and the displacement of the client node is calculated so it displaces in a surface symmetrical fashion to the main node.
   2. CLIENT = POINT_SYM: The point defined by the origin of the coordinate system CS is called the symmetrical point. The nodes (allocated by DVCON_SHAPE operator ND_GROUP) are checked against each other for their symmetry with reference to the symmetrical point. Symmetrical nodes are combined to a symmetrical group (2 symmetrical nodes per symmetrical group is the norm). The main node of the symmetrical group is then determined and the displacement of the client node is calculated so it displaces point symmetrical to the main node. For both symmetrical couplings the given coordinate system in the operator CS must be Cartesian (rectangular). The operator MAIN must have MAX or MIN.
   3. CLIENT = ROTATION_SYM: The specified axis defines the rotation axis of the surface of revolution. The nodes (allocated by DVCON_SHAPE operator ND_GROUP) are checked for their symmetry in the given rotation axis. All nodes at the same parallel of the surface of revolution are combined to a symmetrical group. The main node of the symmetrical group is then determined and the displacement of the client node is calculated so it displaces in a surface symmetrical fashion to the main node.
   4. CLIENT = VECTOR: Referring to the coordinate system entered in the operator CS, the difference between the current coordinates and the start coordinates of the main nodes is calculated. With reference to the coordinate system the start coordinates of the client nodes are then calculated, the difference in the main nodes are determined and the current coordinates of the client nodes are calculated. With VECTOR=ON/OFF, ON/OFF, ON/OFF these coordinates are activated and transferred. The coordinates deactivated remain unchanged.
   5. CLIENT = DIRECTION: The procedure is similar to that of CLIENT = VECTOR with coupling of all three coordinates. The difference is that the obtained displacement vector is scaled to the original absolute value of the displacement of the client node.
   6. CLIENT = LENGTH: The absolute value of displacement of the main nodes is calculated. The displacement of the client nodes is scaled so the absolute value of the obtained displacement of the main node remains.
   7. CLIENT = DISP_CS: The optimization displacement of the main nodes based upon the FE displacement coordinate system is transferred directly in the FE displacement coordinate system of the client nodes. The coupled FE displacement coordinate systems must be of the same kind, that is, either Cartesian, cylindrical, or spherical. With DISP_CS=ON/OFF, ON/OFF, ON/OFF these coordinates that are activated are transferred. The coordinates deactivated remain unchanged.
   8. CLIENT = SURF_PLANE_SYM: The nodes are checked to be symmetric with respect to the given symmetry plane in symmetric but nonsymmetric meshed models. The node corrections are applied in node normal direction only.
   9. CLIENT = SURF_CYCLIC_SYM: Couples nodes in a not necessary symmetric mesh that reoccur in a cyclic manner around a rotational axis.
   10. CLIENT = SURF_CYCLIC_PLANE_SYM: Combination of SURF_CYCLIC_SYM and SURF_PLANE_SYM. Nodes are first coupled in a cyclic manner and then plane symmetry is enforced within each cyclic section. The position of the plane symmetric sections is controlled with the CYCLIC_SYM_START parameter.
   11. CLIENT = SURF_STAMP:
       • The nodes are linked to keep a stampable surface. main nodes are determined automatically.
       • The main options MAX and MIN are not permitted for sensitivity-based optimizations.
   12. CLIENT = SURF_TURN:
       • The nodes are linked to keep a turnable surface. main nodes are determined automatically.
       • The main options MAX and MIN are not permitted for sensitivity-based optimizations.
   13. CLIENT = SURF_DRILL: The nodes are linked to keep a turnable surface. main nodes are determined automatically. The drill restriction is a special combination of the turn and demold restriction.
   14. CLIENT = SURF_DEMOLD: The nodes are linked to keep a castable surface.
4. The CLIENTs PLANE_SYM, ROTATION_SYM, SURF_STAMP, SURF_TURN, SURF_DRILL, SURF_DEMOLD, SURF_CYCLIC_SYM, SURF_PLANE_SYM, SURF_CYCLIC_PLANE_SYM can be used without the AXIS_* parameter. Thus, an arbitrary axis direction <x,y,z> can be specified with reference to CS with the entry CLIENT_DIR = x,y,z. For SURF_STAMP an additional demolding direction can be defined using the DEMOLD_DIR parameter, also available for the definition of the demolding direction for SURF_DEMOLD.
5. CS: Name of the coordinate system that operates LINK_SHAPE. Specifying the coordinate system is essential for CLIENT=PLANE_SYM, POINT_SYM, ROTATION_SYM, VECTOR, DIRECTION, SURF_STAMP, SURF_TURN, SURF_DRILL, SURF_DEMOLD, SURF_CYCLIC_SYM, SURF_PLANE_SYM, or SURF_CYCLIC_PLANE_SYM. Specifying the coordinate system for CLIENT=LENGTH, or DISP_CS is unnecessary. With CLIENT=PLANE_SYM and POINT_SYM only Cartesian coordinate systems are permitted.
6. TOL: Specifying the tolerance values for CLIENT=PLANE_SYM, POINT_SYM, ROTATION_SYM or SURF_DEMOLD is essential. Specifying the tolerance values for CLIENT=VECTOR, DIRECTION, LENGTH, DISP_CS, SURF_STAMP, SURF_TURN, SURF_DRILL, SURF_CYCLIC_SYM, SURF_PLANE_SYM, or SURF_CYCLIC_PLANE_SYM is unnecessary. The tolerance values must be positive. At least one of three tolerance values must be entered. For tolerance values not given, the smallest of the given tolerance values is acceptable. The three tolerance values are also coordinate values referring to the three coordinate directions of the CS. The values of tolerance should be large enough to cover the individual nodes and small enough not to cover any not wanted neighboring nodes.
7. The parameter SURF_PARAM = <main_areas>, <net_points> is used to create a spline that defines the "surface" in the allowed LINK_SHAPE commands. The values <master_areas>, <net_points> are integer values and automatically determined by Tosca Structure. In the event of an error, it might help setting SURF_PARAM. Important is that <master_areas> must be larger than 4 and at least double the size of <net_points>. Good values are, for example, SURF_PARAM = 12, 4.

Examples

LINK_SHAPE
  ID_NAME     = my_link_01
  MAIN        = MAX
  CLIENT      = PLANE_SYM, AXIS_3
  CS          = cs_0
  TOL         = 0.01, 0.01, 0.01
END_

LINK_SHAPE
  ID_NAME     = DEMOLD_AREA
  MAin        = MAX
  CLIENT      = SURF_DEMOLD, AXIS_2
  CS          = cs_0
  ANGLE       = 1.5
  TOL         = 0.01, 0.01, 0.01
  CHECK_GROUP =  CHK_NDGRP_DEMOLD
END_