/DRESP2

Optimization Keyword

/DRESP2 – Design Response via Equations for Design Optimization

Description

When a desired response is not directly available from OptiStruct, it may be calculated using /DRESP2. This response can be a functional combination of any set of responses resulting from the design analysis iteration. Responses defined in this manner can be used as design objectives or constraints. The /DRESP2 card identifies the equation to use for the response relationship and the input values to evaluate the response function.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/DRESP2/resp_ID
title
FUNC	EQID	REGION
VARTYPE1	ID1	ID2	ID3	ID4	ID5	ID6	ID7	ID8	ID9
	ID10	ID11	ID12	...
VARTYPE2	ID1	ID2	ID3	ID4	ID5	ID6	ID7	ID8	ID9
	ID10	ID11	ID12	...
...	...	...	...	...	...	...	...	...	...

Definition

Field	Contents
resp_ID	Design response identifier. (Integer > 0)
title	Title. (Character, maximum 100 characters)
FUNC	Function to be applied to the arguments. (Integer > 0 or blank) = 1: SUM = 2: AVG = 3: SSQ = 4: RSS = 5: MAX = 6: MIN = 7: SUMABS = 8: AVGABS = 9: MAXABS = 10: MINABS
EQID	/DEQATN identifier that defines the response relationship. (Integer > 0 or blank)
REGION	Region identifier Default = 0 (Integer > 0)
VARTYPE#	Indicates the type of variables to follow. (Integer > 0 or blank) = 1: DESVAR = 2: DNODE = 3: DRESP1 = 4: DRESP2 = 5: DVPREL1
ID#	When VARTYPE is DESVAR, DRESP1, DRESP2, or DVPREL1, this list of IDs reference entities of the defined VARTYPE.

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

/DRESP1/1

u_in

### RTYPE=5: Displacement

### PTYPE=1: Node

### ATTA=1 : Translational displacement in X-direction

### ATTI=103 : 103 is node group identifier is due to PTYPE = 1

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

# RTYPE PTYPE REGION ATTA ATTB ATTI

5 1 1 103

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

/DRESP1/2

u_out

### RTYPE=5: Displacement

### PTYPE=1: Node

### ATTA=1 : Translational displacement in X-direction

### ATTI=104 : 104 is node group identifier is due to PTYPE = 1

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

# RTYPE PTYPE REGION ATTA ATTB ATTI

5 1 1 104

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

/DRESP2/4

dresp2

### EQID=1: /DEQATN identifier is 1

### VARTYPE1=3: Indicates the type of variables is 3 (DRESP1)

### ID1=1: first Variable(x) is ID1=1 in DRESP1 (dx in node group 103)

### ID2=2: second Variable(y) is ID2=2 in DRESP1 (dx in node group 104)

# FUNC EQID REGION

# VARTYPE1 ID1 ID2 ID1 ID2 ID1 ID2 ID1 ID2 ID1

3 1 2

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

/DEQATN/1

deqatn

# EQUATIONS

dm(x,y)=(x+y)/2.

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

1.	/DRESP2 entries must have unique identification numbers with respect to /DRESP1 entries.

Any number of VARTYPE# continuation lines can be defined. The order in which the VARTYPE# continuation lines are listed on the /DRESP2 card is not specified. The same VARTYPE# can be repeated any number of times, in any position, on the card. However, the order in which the VARTYPE# continuation lines are listed will affect the solution as the values are passed to the equation (or function) in the listed sequence.

3.	/DRESP2 cannot reference itself directly or recursively, but multiple levels of referencing are allowed.

4.	If VARTYPE is DNODE, a list of NODE could be defined, where every second value is a NODE identifier. For example:

“DNODE, 11, 2” indicates the Y coordinate of NODE Number 11.

Sequence is repeated for VARTYPE = DNODE. For example:

“DNODE, 11, 2, 12, 1” indicates the Y coordinate of NODE Number 11 and X coordinate of NODE Number 12.

5.	The following functions can be used instead of an EQID. If FUNC is used, the /DEQATN entry is no longer needed. The functions are applied to all arguments on the /DRESP2 regardless of their type.

Function	Description	Formula
SUM	Sum of arguments
AVG	Average of arguments
SSQ	Sum of square of arguments
RSS	Square root of sum of squares of arguments
MAX	Maximum of arguments
MIN	Minimum of arguments
SUMABS	Sum of absolute value of arguments
AVGABS	Average of absolute value of arguments
MAXABS	Maximum of absolute arguments
MINABS	Minimum of absolute value of arguments