DSHUFFLE

Bulk Data Entry

DSHUFFLE – Design Variable for Composite Shuffling Optimization

Description

Defines parameters for the generation of composite shuffling design variables.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
DSHUFFLE	ID	ETYPE	EID1	EID2	EID3	EID4	EID5	EID6
+		EID7	…
+	MAXSUCC	MANGLE	MSUCC	VSUCC
+
+	PAIR	PANGLE1	PANGLE2	POPT
+	CORE	CREP	CANG1	CANG2	CANG3	CANG4	CANG5	CANG6
+			CANG7	…
+	COVER	VREP	VANG1	VANG2	VANG3	VANG4	VANG5	VANG6
+			VANG7	…
+	RANGE	PIDSTA	PIDEND

Field	Contents
ID	Unique identification number. No default (Integer > 0)
ETYPE	Entity type for which this DSHUFFLE card is defined. No default (STACK, PCOMP, or PCOMPG)
EID#	Entity identification numbers. List of entities of type ETYPE for which this DSHUFFLE card is defined. No default (Integer > 0)
MAXSUCC	Indicates that the "maximum number of successive plies" constraint is applied. Multiple MAXSUCC constraints are allowed (Comment 1).
MANGLE	Ply orientation, in degrees, to which the MAXSUCC constraint is applied. No default (Real or ALL)
MSUCC	Maximum number of successive plies for the MAXSUCC constraint. No default (Integer > 0)
VSUCC	Allowable percentage violation for the MAXSUCC constraint. 0.0 indicates that this constraint cannot be violated. Default = 0.0 (Real)
PAIR	Indicates that a pairing constraint is applied (Comment 2).
PANGLE1	First ply orientation, in degrees, to which the PAIR constraint is applied. No default (Real, only 45.0 allowed at this time)
PANGLE2	Second ply orientation, in degrees, to which the PAIR constraint is applied. No default (Real, only -45.0 allowed at this time)
POPT	Pairing option. SAME indicates that the stacking sequence should remain the same for consecutive pairs. REVERSE indicates that the stacking sequence should be reversed for alternate pairs. Default = blank (SAME, REVERSE or BLANK)
CORE	Indicates that a ply sequence for the core layer is defined. Only one CORE sequence is allowed (Comment 3).
CREP	Number of times the core ply sequence should be repeated. Default = 1 (Integer > 0)
CANG#	Ply orientations, in degrees, defining the core. No default (Real)
COVER	Indicates that a ply sequence for the cover layer is defined. Only one COVER sequence is allowed (Comment 3).
VREP	Number of times the cover ply sequence should be repeated. Default = 1 (Integer > 0)
VANG#	Ply orientations, in degrees, defining the cover. No default (Real)
RANGE	Indicates that starting and ending ply identification numbers are defined in the following fields to specify the range of plies to be shuffled. OptiStruct will only shuffle plies between PIDSTA and PIDEND. Multiple DSHUFFLE entries can be created to define different ply ranges.
PIDSTA	The ply identification number (starting ply) that defines the first ply in the range to be shuffled. No default (Integer > 0)
PIDEND	The ply identification number (ending ply) that defines the last ply in the range to be shuffled. No default (Integer > 0)

Comments

The MAXSUCC constraint indicates that the stacking sequence should contain no sections with more than a given number of successive plies with the same orientation. In the case of symmetrical laminates, this constraint accounts for the mirrored successive plies on both sides of the symmetry plane. In the image below, (a) shows invalid and valid sequences for a non-symmetrical stack, and (b) shows invalid and valid sequences for a symmetrical stack, both for MAXSUCC=3.

dshuffle_com1

2.	The PAIR constraint indicates that 45° and -45° plies should be paired together. The POPT option specifies how the pairing should be accomplished, as illustrated on the figure below.

dshuffle_com2

The CORE and COVER constraints specify stacking sequences for the core and cover layers, respectively. Plies are listed from the bottom surface upward, in respect to the element’s normal direction. In the example below, the sequence for the core is (0°, 0°, 90°, and 90°) while the sequence for the cover is defined as (90°, 90°, 0°, and 0°).

dshuffle_com3

Note that, for non-symmetrical laminates, COVER actually corresponds to the bottom cover, whereas CORE corresponds to the upper cover. At this point, it is not possible to create an actual core for non-symmetrical stacks.

4.	For a more detailed description and an example, refer to Optimization of Composite Structures in the User’s Guide.

5.	This card is represented as an optimization design variable in HyperMesh.