ANSYS優(yōu)化設(shè)計(含幾個實例)

1、ANSYS優(yōu)化設(shè)計1. 認(rèn)識ANSYS優(yōu)化模塊1.1什么時候我需要它的幫忙？什么是ANSYS優(yōu)化？我想說明一個例子要比我在這里對你絮叨半天容易理解的多。注意過普通的水杯嗎？底面圓圓的，上面加蓋的哪一種。仔細(xì)觀察一下，你會發(fā)現(xiàn)比較老式的此類水杯有一個共同特點：底面直徑=水杯高度。圖1水杯的簡化模型為什么是這樣呢？因為只有滿足這個條件，才能在原料耗費最少的情況下使杯子的容積最大。在材料一定的情況下，如果水杯的底面積大，其高度必然就要??；如果高度變大了， 底面積又大不了，如何調(diào)和這兩者之間的矛盾？其實這恰恰就反應(yīng)了一個完整的優(yōu)化過程。在這里，一個水杯的材料是一定的，所要優(yōu)化的變量就是杯子底面的半徑

2、r和杯子的高 度h,在ANSYS的優(yōu)化模塊里面把這些需要優(yōu)化的變量叫做設(shè)計變量（ DV ）;優(yōu)化的目標(biāo) 是要使整個水杯的容積最大， 這個目標(biāo)在ANSYS的優(yōu)化過程里叫目標(biāo)函數(shù) （OBJ）;再者, 對設(shè)計變量的優(yōu)化有一定的限制條件， 比如說整個杯子的材料不變，這些限制條件在ANSYS 的優(yōu)化模塊中用狀態(tài)變量（SV）來控制。下面我們就來看看 ANSYS中怎么通過設(shè)定 DV、SV、OBJ，利用優(yōu)化模塊求解以上問題。首先參數(shù)化的建立一個分析文件（假設(shè)叫volu.inp ），水杯初始半徑為 R= 1，高度為H=1 （DV ）,由于水杯材料直接喝水杯的表面積有關(guān)系，這里假設(shè)水杯表面積不能大于100,2 2

3、這樣就有 S= 2 n RH + 2 nR SOLUTION HAS CONVERGED TO POSSIBLE OPTIMUM （BASED ON OBJ TOLERANCE BETWEEN BEST AND FINAL DESIGNS）可見是因為導(dǎo)致循環(huán)提前結(jié)束。（注：細(xì)觀上圖，F(xiàn)j=157.20, Fb=151.62，默認(rèn)公差似乎此處應(yīng)該是1.5720,似乎還沒有滿足這個收斂準(zhǔn)則，為什么 ANSYS卻認(rèn)為滿足了，這里就不 得而知，可能ANSYS內(nèi)部對默認(rèn)公差里面的當(dāng)前值另有解釋；如果你強行規(guī)定目標(biāo)函數(shù)公差為1,可以看到循環(huán)多進行一步后也會提前結(jié)束，不過這時候當(dāng)前解151.65和最優(yōu)解15

4、1.62倒的確相差小于公差 1 了）。此時，大家一定可以理解例子中為什么要對公差的限制如此嚴(yán) 謹(jǐn)了（ 0.01）。因為程序的取樣，迭代都有隨機性，只有這樣，才能保證程序不會因為上述 公差太大的緣故自動停止而得不到最優(yōu)解。有興趣的同學(xué)還可以改變一下其他參數(shù)的公差大小，甚至用opsubp命令改變默認(rèn)循環(huán)的次數(shù)等，這些實驗將會更加加深你對優(yōu)化過程、 收斂準(zhǔn)則的理解，便于提高你都負(fù)責(zé)優(yōu)化 問題的駕馭能力。歡迎下載拓?fù)鋬?yōu)化實例BLC4,0,0,3,1ET,1,82ET,2,82 MP,EX,1,118E9 MP,NUXY,1,0.3ESIZE,0.05TYPE,1 AMESH,ALLNSEL,S ,L

5、OC,X,0,0.4ESLNNSEL,S, LOC,X,0D,ALL,ALL,0NSEL,S, LOC,X,3D,ALL,ALL,0FORCE = 1000! Fixed at X = 0! Fixed at X = 3! Value for applied loadNSEL,S ,L OC,X,1NSEL,R, LOC,Y,1 F,ALL,FY,FORCE ALLSEL! Define first load caseLSWRITE,1FDEL,ALLNSEL,S, LOC,X,2NSEL,R, LOC,Y,0 F,ALL,FY,-FORCE ALLSEL! Write first load

6、case! Defi ne sec ond load case/clear /TITLE, A 2-D, multiple compliance minimization problem subjected to volume constraint /PREP7 ! Create solid model (3 x 1 recta ngle) ! Use 2-D solids. Type 1 is optimized ! Type 2 is not optimized.! Lin ear isotropic, material ! Use a relatively fine mesh densi

7、ty! Free, recta ngular-eleme nt mesh ing! Select regi on not to be optimizedTYPE,2! Define type 2 eleme ntsEMODIF,ALL! Write sec ond load caseLSWRITE,2FDEL,ALLTOCOMP,MCOMP,MULTIPLE,2 ! Define multiple complia nee fun ctio n! MCOMP for topological optimizati onTOVAR,MCOMP,OBJ! Define MCOMP as topolog

8、ical objectiveTOVAR,VOLUME,CON,50! Defi ne VOLUME as topological co nstrai nt; 50 perce ntvolume reduct ionTOTYPE,OCTODEF/SHOW,topo,grph/DSCALE,OFF! Specify soluti on approach! In itialize topological opt.! Put graphics in a file (remove if in teractive)ALLSEL/CONTOUR,2TOLOOP,12,1FINISH! Perform no

9、more than 12 iterationsTOGRAPH,OBJ TOGRAPH,CON TOPRINT,OBJ TOPRINT,CON! Graph final objective (complia nee) history! Graph final con stra in t (volume) history! Print final objective (complianee) history! Print final constraint (volume) history*GET,TITER,TOPO,ITER! Get iteratio n counter*GET,OCMP,TO

10、PO,TITER-1,TOHO ! Get fin al complia nee value第3例復(fù)雜形狀實體的創(chuàng)建實例一螺栓本例提示在使用ANSYS軟件進行結(jié)構(gòu)分析時，建立實體模型是最復(fù)雜最難以掌握 的一個過程。因此，有必要熟練掌握實體模型的創(chuàng)建。本例使用ANSYS軟件提供的各種建模工具，對復(fù)雜形狀實體的創(chuàng)建進行了練習(xí)。/PREP7CSYS,1K,1,0.008,0,-0.002K,2,0.008,90,-0.0015K,3,0.008,180,-0.001K,4,0.008,270,-0.0005K,5,0.008,0,0/VIEW,1,1,1,1L, 1,2L,2,3L,3,4L,4,5

11、LGEN,7,ALL,0.002NUMMRG,KP,LOWLCOMB,ALLK,80,0.008+0.0015/4,90,0.012+0.002/4K,81,0.008+2*0.0015/4,180,0.012+2*0.002/4K,82,0.008+3*0.0015/4,270,0.012+3*0.002/4K,83,0.008+4*0.0015/4,0,0.012+4*0.002/4L, 35,80L,80,81L,81,82L,82,83CSYS,0K,90,0.008,0,-0.00025K,91,0.006918,0,-0.002K,92,0.006918,0,0/PNUM,KP,1

12、/PNU M,L INE,1GPLOTLSTR,1,90LSTR,91,92LANG,7,90,60,0LANG,7,1,120,0AL,6,9,10,11VDRAG,1,1,2,3,4,5/PNUM,KP,0/PNU M,L INE,0/PNUM,AREA,1/PNUM,VOLU,1CYLIND,0.0079,0,0.04,0,360VSEL,U,6CM,VVV2,VOLUALLSVSBV,6,VVV2/REPLOTK,93,0.0065,0,0K,94,0.0095,0,0.003K,95,0,0,0K,96,0,0,0.03LSTR,93,94AROTAT,6,95,96,360ASEL

13、,S,1,4,1VSBA,7,ALLASEL,ALLVDELE,1,1RPRISM,0.04,0.05,6,0.0131CONE,0.03477,0.00549,0.03,0.055,0,360VINV,1,3/REPLOTVPLOTFINISH第26例優(yōu)化設(shè)計實例一梁的優(yōu)化設(shè)計本例提示介紹了優(yōu)化設(shè)計的相關(guān)理論和應(yīng)用，講述了將設(shè)計問題的物理模型轉(zhuǎn)化為 數(shù)學(xué)模型一選取設(shè)計變量、寫出目標(biāo)函數(shù)、給出約束條件的方法。1. 優(yōu)化分析文件!File : EXAMPLE26LGWH=0.06B=0.06L=1/PREP7ET,1, BEAM3R,1,B*H,B*H*H*H/12,HMP,EX,1,2E11M

14、P,NUXY,1,0.3K,1,0,0,0K,2, L,0,0LSTR,1,2LESIZE,1,50LMESH,1FINISH/SOLUDK,1,UXDK,1,UYDK,2,UXDK,2,UYSFBEAM,ALL,1,PRES,5000SOLVESAVEFINISH/P0ST1ETABLE,E_VOL,VOLUSSUM*GET,V_TOT,SSUM,ITEM,E_VOLNSORT,U,Y*GET,UY_MIN,SORT,MINUY_MAX=ABS(UY_MIN)FINISH2. 優(yōu)化控制文件!File : EXAMPLE26_OPT.TXT/FILNAME, EXAMPLE26/OPTOPCL

15、RFINISH/CLEAR/INPUT, EXAMPLE26,LGW/OPTOPANL, EXAMPLE26 ,L GWOPVAR,B,DV,O.O5,O.1,O.OO1OPVAR,H,DV,O.O5,O.1,O.OO1OPVAR,UY_MAX,SV,O,2E-4,1E-5OPVAR,V_TOT,OBJ,1E-5OPSAVE, EXAMPLE26,OPTOPTYPE, FIRSTOPFRST,3OOPEXECOPLIST,ALLFINISH3. 求解方法先分別以文件名 EXAMPLE26.LGW、EXAMPLE26_OPT.TXT 將優(yōu)化分析文件和優(yōu)化 控制文件存儲在ANSYS的工作文件夾里，

16、再在ANSYS的輸入窗口輸入 /INPUT,EXAMPLE26_OPT,TXT ，回車，開始求解。第27例優(yōu)化設(shè)計實例一曲柄搖桿機構(gòu)的優(yōu)化設(shè)計本例提示介紹了一個更復(fù)雜、更接近于實際的優(yōu)化設(shè)計實例。叵片舞工4.44。M虐的軌跡耳目棟位羞點曲線的姑比情:兄1. 優(yōu)化分析文件!File : EXAMPLE27丄GWPl=3.1415926A=2B=8C=7.5D=9.5AX=1AY=4BATA_0PT=PI/16K=7GAMA=PI/3!建立有限元模型/PREP7BATA=BATA_0PT-PI/2OMGA1=0.5T=60/OMGA1ET,1,COMBIN7ET,2,BEAM4MP,EX,1,2E

17、11MP,PRXY,1,0.3MP,DENS,1,1E-14R,1,1E9,1E3,1E3,0R,2,4E-4,1.3333E-8,1.3333E-8,0.02,0.02C0S_SETA1=(A+B)*(A+B)+D*D-C*C)/2/(A+B)/D*IF,C0S_SETA1,GE,-1,AND,C0S_SETA1,LE,1,THENSETA 仁AC0S(C0S_SETA1)*ELSESETA 仁0*ENDIFBX=AX+A*C0S(SETA1+BATA)BY=AY+A*SIN(SETA1+BATA)CX=BX+B*C0S(SETA1+BATA)CY=BY+B*SIN(SETA1+BATA)D

18、X=AX+D*COS(BATA)DY=AY+D*SIN(BATA)KX=BX+K*C0S(BATA+SETA1+GAMA)KY=BY+K*SIN(BATA+SETA1+GAMA)N,1,AX,AYN,2,BX,BYN,3,BX,BYN,4,CX,CYN,5,CX,CYN,6,DX,DYN,7,BX,BY,-1N,8,CX,CY,-1N,9,KX,KYTYPE,1REAL,1E,2,3,7E,4,5,8TYPE,2REAL,2E,1,2E,3,4E,5,6E,3,9E,4,9FINISH!求解/SOLUANTYPE,TRANSNLGEOM,ONDELTIM,T/100KBC,0TIME,TOUT

19、RES,BASIC,ALLAUTOTS,ONCNVTOL,F,1,0.1CNVTOL,M,1,0.1D,ALL,UZD,ALL,ROTXD,ALL,ROTYD,1,ROTZ,2*PI-O.OO1D,1,UXD,1,UYD,6,UXD,6,UYSOLVESAVEFINISH!提取數(shù)據(jù)/POST26*DIM,X_OBJ,ARRAY,10*DIM,Y_OBJ,ARRAY,10X_OBJ(1)=9.5Y_OBJ(1)=8.26X_OBJ(2)=9Y_OB J( 2)=8.87X_OB J( 3)=7.97Y_OB J( 3)=9.51X_OB J(4)=5.65Y_OB J(4)=9.94X_OB J

20、( 5)=4.36Y_OBJ(5)=9.7X_OB J( 6)=3.24Y_OBJ(6)=9X_OB J=3.26Y_OB J=8.36X_OBJ(8)=4.79Y_OBJ(8)=8.11X_OBJ(9)=6.58Y_OBJ(9)=8X_OBJ(10)=9.12Y_OBJ(10)=7.89X_OBJ_MIN=3.24X_OBJ_MAX=9.5NSOL,2,9,UXNSOL,3,9,UY*DIM,X9,ARRAY,100*DIM,Y9,ARRAY,100VGET,X9,2VGET,Y9,3*DO,I,1,100X9(I)=KX+X9(I)Y9(I)=KY+Y9(I)*ENDDOG2=B+C-A-

21、DG3=C+D-A-BG4=B+D-A-CC0S_GAMA1=(B*B+C*C-(D-A)*(D-A)/2/B/CCOS_GAMA2=(B*B+C*C-(D+A)*(D+A)/2/B/C*IF,COS_GAMA1,GE,-1,AND,COS_GAMA1,LE,1,THENG5=ACOS(COS_GAMA1)-3O*PI/18O*ELSEG5=-1*ENDIF*IF,COS_GAMA2,GE,-1,AND,COS_GAMA2 ,L E,1,THENG6=15O*PI/18O-ACOS(COS_GAMA2)*ELSEG6=-1*ENDIFF2=0*DO,I,1,10F2=F2+(Y9(I*1O)-

22、Y_OBJ (I) )*(Y9(I*10)-Y_OB J(I) )+(X9(l*1O)-X_OBJ(l)*(X9(l*1O)-X_OBJ(I)*ENDDOFINISH2. 優(yōu)化控制文件!File : EXAMPLE27_OPT.TXT/OPTOPCLRFINISH !/CLEAR/INPUT, EXAMPLE27,LGW/OPTOPANL, EXAMPLE27 ,L GWOPVAR,A,DV,0.1,10,0.001OPVAR,B,DV,0.1,10,0.001OPVAR,C,DV,O.1,1O,O.OO1OPVAR,D,DV,0.1,10,0.001OPVAR,AX,DV,0.1,5,0.001OPVAR,AY,DV,0.1,5,0.001OPVAR,BATA_OPT,DV,0.1,