优化设计实例.docx
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优化设计实例
第26例优化设计实例—梁的优化设计
[本例提示]介绍了优化设计的相关理论和应用,讲述了将设计问题的物理模型转化为数学模型—选取设计变量、写出目标函数、给出约束条件的方法。
1.优化分析文件
!
File:
EXAMPLE26.LGW
H=0.06
B=0.06
L=1
/PREP7
ET,1,BEAM3
R,1,B*H,B*H*H*H/12,H
MP,EX,1,2E11
MP,NUXY,1,0.3
K,1,0,0,0
K,2,L,0,0
LSTR,1,2
LESIZE,1,,,50
LMESH,1
FINISH
/SOLU
DK,1,UX
DK,1,UY
DK,2,UX
DK,2,UY
SFBEAM,ALL,1,PRES,5000
SOLVE
SAVE
FINISH
/POST1
ETABLE,E_VOL,VOLU
SSUM
*GET,V_TOT,SSUM,,ITEM,E_VOL
NSORT,U,Y
*GET,UY_MIN,SORT,,MIN
UY_MAX=ABS(UY_MIN)
FINISH
2.优化控制文件
!
File:
EXAMPLE26_OPT.TXT
/FILNAME,EXAMPLE26
/OPT
OPCLR
FINISH
/CLEAR
/INPUT,EXAMPLE26,LGW
/OPT
OPANL,EXAMPLE26,LGW
OPVAR,B,DV,0.05,0.1,0.001
OPVAR,H,DV,0.05,0.1,0.001
OPVAR,UY_MAX,SV,0,2E-4,1E-5
OPVAR,V_TOT,OBJ,,,1E-5
OPSAVE,EXAMPLE26,OPT
OPTYPE,FIRST
OPFRST,30
OPEXEC
OPLIST,ALL
FINISH
3.求解方法
先分别以文件名EXAMPLE26.LGW、EXAMPLE26_OPT.TXT将优化分析文件和优化控制文件存储在ANSYS的工作文件夹里,再在ANSYS的输入窗口输入/INPUT,EXAMPLE26_OPT,TXT,回车,开始求解。
第27例优化设计实例—曲柄摇杆机构的优化设计
本例提示]介绍了一个更复杂、更接近于实际的优化设计实例。
1.优化分析文件
!
File:
EXAMPLE27.LGW
PI=3.1415926
A=2
B=8
C=7.5
D=9.5
AX=1
AY=4
BATA_OPT=PI/16
K=7
GAMA=PI/3
!
建立有限元模型
/PREP7
BATA=BATA_OPT-PI/2
OMGA1=0.5
T=60/OMGA1
ET,1,COMBIN7
ET,2,BEAM4
MP,EX,1,2E11
MP,PRXY,1,0.3
MP,DENS,1,1E-14
R,1,1E9,1E3,1E3,0
R,2,4E-4,1.3333E-8,1.3333E-8,0.02,0.02
COS_SETA1=((A+B)*(A+B)+D*D-C*C)/2/(A+B)/D
*IF,COS_SETA1,GE,-1,AND,COS_SETA1,LE,1,THEN
SETA1=ACOS(COS_SETA1)
*ELSE
SETA1=0
*ENDIF
BX=AX+A*COS(SETA1+BATA)
BY=AY+A*SIN(SETA1+BATA)
CX=BX+B*COS(SETA1+BATA)
CY=BY+B*SIN(SETA1+BATA)
DX=AX+D*COS(BATA)
DY=AY+D*SIN(BATA)
KX=BX+K*COS(BATA+SETA1+GAMA)
KY=BY+K*SIN(BATA+SETA1+GAMA)
N,1,AX,AY
N,2,BX,BY
N,3,BX,BY
N,4,CX,CY
N,5,CX,CY
N,6,DX,DY
N,7,BX,BY,-1
N,8,CX,CY,-1
N,9,KX,KY
TYPE,1
REAL,1
E,2,3,7
E,4,5,8
TYPE,2
REAL,2
E,1,2
E,3,4
E,5,6
E,3,9
E,4,9
FINISH
!
求解
/SOLU
ANTYPE,TRANS
NLGEOM,ON
DELTIM,T/100
KBC,0
TIME,T
OUTRES,BASIC,ALL
AUTOTS,ON
CNVTOL,F,1,0.1
CNVTOL,M,1,0.1
D,ALL,UZ
D,ALL,ROTX
D,ALL,ROTY
D,1,ROTZ,2*PI-0.001
D,1,UX
D,1,UY
D,6,UX
D,6,UY
SOLVE
SAVE
FINISH
!
提取数据
/POST26
*DIM,X_OBJ,ARRAY,10
*DIM,Y_OBJ,ARRAY,10
X_OBJ
(1)=9.5
Y_OBJ
(1)=8.26
X_OBJ
(2)=9
Y_OBJ
(2)=8.87
X_OBJ(3)=7.97
Y_OBJ(3)=9.51
X_OBJ(4)=5.65
Y_OBJ(4)=9.94
X_OBJ(5)=4.36
Y_OBJ(5)=9.7
X_OBJ(6)=3.24
Y_OBJ(6)=9
X_OBJ(7)=3.26
Y_OBJ(7)=8.36
X_OBJ(8)=4.79
Y_OBJ(8)=8.11
X_OBJ(9)=6.58
Y_OBJ(9)=8
X_OBJ(10)=9.12
Y_OBJ(10)=7.89
X_OBJ_MIN=3.24
X_OBJ_MAX=9.5
NSOL,2,9,UX
NSOL,3,9,UY
*DIM,X9,ARRAY,100
*DIM,Y9,ARRAY,100
VGET,X9,2
VGET,Y9,3
*DO,I,1,100
X9(I)=KX+X9(I)
Y9(I)=KY+Y9(I)
*ENDDO
G2=B+C-A-D
G3=C+D-A-B
G4=B+D-A-C
COS_GAMA1=(B*B+C*C-(D-A)*(D-A))/2/B/C
COS_GAMA2=(B*B+C*C-(D+A)*(D+A))/2/B/C
*IF,COS_GAMA1,GE,-1,AND,COS_GAMA1,LE,1,THEN
G5=ACOS(COS_GAMA1)-30*PI/180
*ELSE
G5=-1
*ENDIF
*IF,COS_GAMA2,GE,-1,AND,COS_GAMA2,LE,1,THEN
G6=150*PI/180-ACOS(COS_GAMA2)
*ELSE
G6=-1
*ENDIF
F2=0
*DO,I,1,10
F2=F2+(Y9(I*10)-Y_OBJ(I))*(Y9(I*10)-Y_OBJ(I))+(X9(I*10)-X_OBJ(I))*(X9(I*10)-X_OBJ(I))
*ENDDO
FINISH
2.优化控制文件
!
File:
EXAMPLE27_OPT.TXT
/OPT
OPCLR
FINISH !
/CLEAR
/INPUT,EXAMPLE27,LGW
/OPT
OPANL,EXAMPLE27,LGW
OPVAR,A,DV,0.1,10,0.001
OPVAR,B,DV,0.1,10,0.001
OPVAR,C,DV,0.1,10,0.001
OPVAR,D,DV,0.1,10,0.001
OPVAR,AX,DV,0.1,5,0.001
OPVAR,AY,DV,0.1,5,0.001
OPVAR,BATA_OPT,DV,0.1,PI,0.001
OPVAR,K,DV,0,10,0.001
OPVAR,GAMA,DV,0.1,PI,0.001
OPVAR,G2,SV,0,100
OPVAR,G3,SV,0,100
OPVAR,G4,SV,0,100
OPVAR,G5,SV,0,100
OPVAR,G6,SV,0,100
OPVAR,F2,OBJ,,,0.001
OPSAVE,EXAMPLE27,OPT
OPTYPE,FIRST
OPEXEC
OPLIST,ALL
FINISH
3.求解方法
先分别以文件名EXAMPLE27.LGW、EXAMPLE27_OPT.TXT将优化分析文件和优化控制文件存储在ANSYS的工作文件夹里,再在ANSYS的输入窗口输入/INPUT,EXAMPLE27_OPT,TXT,回车,开始求解。