BEAD

Bulk Data Entry Defines parameters for the generation of topography design variables.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
BEAD BID MW ANG BF HGT norm/XD YD ZD SKIP
FID/XF YF ZF AID/XA YA ZA LB UB TYP
SID/XS YS ZS UCYC

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
BEAD 1 3.0 60.0 yes 5.0 norm both
0.0 1.0 0.0 0.0 25.0 0.0 50
1.0 0.0 0.0 3

Definitions

Field Contents
BID PID or DID (Integer > 0; no default). This field can contain the PSHELL or PCOMP property ID of the elements or the desvar number of any set of DVGRIDs present in the deck to be optimized for topography. If field 6 contains data, OptiStruct will assume that the BEAD card references a property, otherwise it assumes that the card references a DESVAR and its corresponding DVGRIDs.
MW Bead minimum width (Real > 0.0; no default). This parameter controls the width of the beads in the model [recommended value between 1.5 and 2.5 times the average element width]. 1
ANG Draw angle in degrees (1.0 < Real < 89.0; no default). This parameter controls the angle of the sides of the beads [recommended value between 60 and 75 degrees]. 1
BF Buffer zone ('yes' or 'no'; default = 'yes'). This parameter will establish a buffer zone between elements in the design domain and elements outside the design domain.
HGT Draw height: (Real > 0.0; no default). This parameter sets the maximum height of the beads to be drawn. This field is only valid if a PID is declared in field 2.
norm/XD,YD,ZD Draw direction ('norm' in field 7 or Real in all three fields; default = 'norm'). If field 7 is 'norm', the shape variables will be created in the normal directions of the elements. If all the fields are real, the shape variable will be created in the direction specified by the xyz vector defined by fields 7, 8, and 9. The X, Y, and Z values are in the basic coordinate system. This field is only valid if a PID is declared in field 2.
SKIP Boundary skip ('both', 'bc', 'spc', 'load', or 'none'; default = 'both'). This parameter tells OptiStruct to leave certain nodes out of the design domain. If 'none', all nodes attached to elements whose PID was specified in field 2 will be a part of the shape variables. If 'bc' or 'spc', any nodes which have SPC or SPC1 declarations are omitted from the design domain. If 'load', any nodes which have FORCE, FORCE1, MOMENT, MOMENT1, or SPCD declarations are omitted from the design domain. If 'both', nodes with either 'spc' or 'load' declarations are omitted from the design domain. This field is only valid if a PID is declared in field 2.
FID/XF,YF,ZF Direction of first vector for variable pattern grouping (Real in all three fields or Integer in field 12; default = blank). These fields define an xyz vector which determines how grids are grouped into variables. The X, Y, and Z values are in the global coordinate system. You may put a grid ID in field 12 to define the first vector. This vector goes from the anchor point to this grid. If all fields are blank and field 20 is not blank or zero, OptiStruct gives an error.
AID/XA,YA,ZA Variable grouping pattern anchor point (Real in all three fields or integer in field 15; default = blank). These fields define a point which determines how grids are grouped into variables. The X, Y, and Z values are in the global coordinate system. You may put a grid ID in field 15 to define the anchor point.
LB Lower bound on variables controlling grid movement (Real < UB, default = 0.0). This sets the lower bound on grid movement equal to LB*HGT.
UB Upper bound on variables controlling grid movement (Real > LB, default = 1.0). This sets the upper bound on grid movement equal to UB*HGT.
TYP Type of variable grouping pattern. (Integer ≥ 0, default = 0) Required if any symmetry or variable pattern grouping is desired. If zero or blank, anchor node, first vector, and second vector definitions are ignored. If less than 20, second vector definition is ignored.
SID/XS,YS,ZS Direction used to determine second vector for variable pattern grouping (Real in all three fields or Integer in field 22; default = blank). These fields define an xyz vector which, when combined with the first vector, form a plane. The second vector is calculated to lie in that plane and is perpendicular to the first vector. The second vector is sometimes required to determine how grids are grouped into variables. The X, Y, and Z values are in the global coordinate system. You may put a grid ID in field 22 to define the second vector. This vector goes from the anchor point to this grid. If all fields are blank and field 20 contains a value of 20 or higher, OptiStruct gives an error.
UCYC Number of cyclical repetitions for cyclical symmetry (Integer ≥ 0 or blank; default = 0). This field defines the number of radial "wedges" for cyclical symmetry. The angle of each wedge is computed as 360.0 / UCYC.

Comments

  1. The BEAD Bulk Data Entry will no longer be supported for the definition of topography optimization. All definitions must be provided using the DTPG Bulk Data Entry. HyperMesh will continue to read BEAD entries, but will convert them into DTPG entries.