/DRESP2
Optimization Keyword 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  etc  
VARTYPE2  ID1  ID2  ID3  ID4  ID5  ID6  ID7  ID8  ID9 
ID10  ID11  ID12  etc  
etc  etc  etc  etc  etc  etc  etc  etc  etc  etc 
Definitions
Field  Contents  SI Unit Example 

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) 

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) 

ID#  When VARTYPE is DESVAR, DRESP1, DRESP2, or DVPREL1, this list of IDs reference entities of the defined VARTYPE. 
Example
#12345678910
/DRESP1/1
u_in
### RTYPE=5: Displacement
### PTYPE=1: Node
### ATTA=1 : Translational displacement in Xdirection
### ATTI=103 : 103 is node group identifier is due to PTYPE = 1
#12345678910
# RTYPE PTYPE REGION ATTA ATTB ATTI
5 1 1 103
#12345678910
/DRESP1/2
u_out
### RTYPE=5: Displacement
### PTYPE=1: Node
### ATTA=1 : Translational displacement in Xdirection
### ATTI=104 : 104 is node group identifier is due to PTYPE = 1
#12345678910
# RTYPE PTYPE REGION ATTA ATTB ATTI
5 1 1 104
#12345678910
/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
1
# VARTYPE1 ID1 ID2 ID1 ID2 ID1 ID2 ID1 ID2 ID1
3 1 2
#12345678910
/DEQATN/1
deqatn
# EQUATIONS
dm(x,y)=(x+y)/2.
#12345678910
Comments
 /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.
 /DRESP2 cannot reference itself directly or recursively, but multiple levels of referencing are allowed.
 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.
 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 $\mathrm{SUM}\left({y}_{1},{y}_{2}\cdot \cdot \cdot {y}_{m}\right)={\displaystyle \sum _{i=1}^{m}{y}_{i}}$ AVG Average of arguments $\mathrm{AVG}\left({y}_{1},{y}_{2}\cdot \cdot \cdot {y}_{m}\right)=\frac{{\displaystyle \sum _{i=1}^{m}{y}_{i}}}{m}$ SSQ Sum of square of arguments $\mathrm{SSQ}\left({y}_{1},{y}_{2}\cdot \cdot \cdot {y}_{m}\right)={\displaystyle \sum _{i=1}^{m}{y}_{i}^{2}}$ RSS Square root of sum of squares of arguments $\mathrm{RSS}\left({y}_{1},{y}_{2}\cdot \cdot \cdot {y}_{m}\right)=\sqrt{{\displaystyle \sum _{i=1}^{m}{y}_{i}^{2}}}$ MAX Maximum of arguments MIN Minimum of arguments SUMABS Sum of absolute value of arguments $\mathrm{SUM}\left({y}_{1},{y}_{2}\cdot \cdot \cdot {y}_{m}\right)={\displaystyle \sum _{i=1}^{m}\left{y}_{i}\right}$ AVGABS Average of absolute value of arguments $\mathrm{AVG}\left({y}_{1},{y}_{2}\cdot \cdot \cdot {y}_{m}\right)=\frac{{\displaystyle \sum _{i=1}^{m}\left{y}_{i}\right}}{m}$ MAXABS Maximum of absolute arguments MINABS Minimum of absolute value of arguments