Ansys算PCM微管的热应力一问(相变、热应力)

cookyzhao

使用间接法计算一个无限长的PCM微管在降温复温过程中内管壁处经历的热应力，
结果发现不管怎么调整网格和时间步，降温凝固阶段的应力峰总是有两个挨的很近的峰组成
，而复温溶解初始阶段的应力峰却是单峰。以前使用有限差分方法，都是只有一个峰。
不知道问题出在哪里？还请指点，谢谢！

网格划分、结果图如附件所示。

程序源文件如下：
/config,nres,1000000
/filname, thermal stress
/title, Thermal Stress in an Infinite Long Cylindric PCM
/PAGE, ILINE, ICHAR, BLINE, BCHAR

/prep7
et,1,plane77,,,1
! keyopt,1,3,1

MPTEMP,,,,,,,,
MPTEMP,1,-120
MPTEMP,2,-62.5
MPTEMP,3,-20.887
MPTEMP,4,-17.5
MPTEMP,5,-13.145
MPTEMP,6,-10.081
MPTEMP,7,-7.1774
MPTEMP,8,-5.2419
MPTEMP,9,-3.629
MPTEMP,10,-2.3387
MPTEMP,11,-1.5323
MPTEMP,12,-0.8871
MPTEMP,13,-0.40323
MPTEMP,14,0.080645
MPTEMP,15,25.081
MPDATA,KXX,1,,2.24
MPDATA,KXX,1,,2.2397
MPDATA,KXX,1,,2.2371
MPDATA,KXX,1,,2.2185
MPDATA,KXX,1,,2.1788
MPDATA,KXX,1,,2.1099
MPDATA,KXX,1,,1.9616
MPDATA,KXX,1,,1.7894
MPDATA,KXX,1,,1.5642
MPDATA,KXX,1,,1.2993
MPDATA,KXX,1,,1.0768
MPDATA,KXX,1,,0.88079
MPDATA,KXX,1,,0.71391
MPDATA,KXX,1,,0.561
MPDATA,KXX,1,,0.561

MPTEMP,,,,,,,,
MPTEMP,1,-120
MPTEMP,2,-60.092
MPTEMP,3,-34.286
MPTEMP,4,-20.276
MPTEMP,5,-14.747
MPTEMP,6,-11.797
MPTEMP,7,-8.8479
MPTEMP,8,-6.6359
MPTEMP,9,-5.1613
MPTEMP,10,-3.6866
MPTEMP,11,-2.5806
MPTEMP,12,-1.4747
MPTEMP,13,-0.73733
MPTEMP,14,0.36866
MPTEMP,15,24.7
MPDATA,ENTH,1,,0
MPDATA,ENTH,1,,1.16E+08
MPDATA,ENTH,1,,1.65E+08
MPDATA,ENTH,1,,1.93E+08
MPDATA,ENTH,1,,2.08E+08
MPDATA,ENTH,1,,2.24E+08
MPDATA,ENTH,1,,2.47E+08
MPDATA,ENTH,1,,2.77E+08
MPDATA,ENTH,1,,3.18E+08
MPDATA,ENTH,1,,3.55E+08
MPDATA,ENTH,1,,3.94E+08
MPDATA,ENTH,1,,4.45E+08
MPDATA,ENTH,1,,4.90E+08
MPDATA,ENTH,1,,5.21E+08
MPDATA,ENTH,1,,6.23E+08

RECTNG,0.0042,0.0053,0,0.000055
type,1
lsel,s,line,,1,3,2
lesize,all,,,40
lsel,s,line,,2,4,2
lesize,all,,,2
allsel
amesh,1
finish

/solu
antype, trans
bfunif,temp,0

Bc=5  !降温速率
Bw=100   !复温速率
*DIM,temp_time,TABLE,5,,,time
*SET,TEMP_TIME(1,0),0,60*120/Bc,60*(120/Bc+15),60*(120/Bc+15+120/Bw), 60*(120/Bc+15+120/Bw+15)    !!内外壁面处温度历史表格
*SET,TEMP_TIME(1,1) , 0, -120,-120,0,0  
ftime=60*(120/Bc+15+120/Bw+15)

!*DIM,temp_time,TABLE,2,,,time
!*SET,TEMP_TIME(1,0),0,60*120/Bc
!*SET,TEMP_TIME(1,1) , 0, -120
!ftime=60*120/Bc

time0=0
tinc=1
delt=30

DL,2,,temp,%temp_time%,1
DL,4,,temp,%temp_time%,1
allsel

kbc,1
autots,on
deltim,1,0.05,6,on
timint,on
tintp,,,,1
lnsrch,1
outres,basic,all
allsel
physics,write,thermal

/prep7
lsclear,all
etchg,tts
keyopt,1,3,1
keyopt,1,6,1
mp,ex,1,2.5E9
mp,nuxy,1,0.33

MPTEMP,,,,,,,,
MPTEMP,1,-120
MPTEMP,2,-22.177
MPTEMP,3,-18.629
MPTEMP,4,-16.048
MPTEMP,5,-14.113
MPTEMP,6,-12.339
MPTEMP,7,-10.565
MPTEMP,8,-9.4355
MPTEMP,9,-7.9839
MPTEMP,10,-7.0161
MPTEMP,11,-6.2097
MPTEMP,12,-5.7258
MPTEMP,13,-4.7581
MPTEMP,14,-3.4677
MPTEMP,15,-2.6613
MPTEMP,16,-1.8548
MPTEMP,17,-1.2097
MPTEMP,18,-0.40323
MPTEMP,19,0.080645
MPTEMP,20,25.403
MPDATA,DENS,1,,917
MPDATA,DENS,1,,916.97
MPDATA,DENS,1,,917.69
MPDATA,DENS,1,,918.52
MPDATA,DENS,1,,919.24
MPDATA,DENS,1,,920.79
MPDATA,DENS,1,,922.58
MPDATA,DENS,1,,924.6
MPDATA,DENS,1,,927.82
MPDATA,DENS,1,,930.92
MPDATA,DENS,1,,934.5
MPDATA,DENS,1,,937.24
MPDATA,DENS,1,,942.01
MPDATA,DENS,1,,951.66
MPDATA,DENS,1,,959.77
MPDATA,DENS,1,,969.42
MPDATA,DENS,1,,979.44
MPDATA,DENS,1,,991.95
MPDATA,DENS,1,,1000
MPDATA,DENS,1,,1000

MPTEMP,,,,,,,,  

MPTEMP,1,-120
MPTEMP,2,-78.306
MPTEMP,3,-45.242
MPTEMP,4,-21.532
MPTEMP,5,-18.468
MPTEMP,6,-14.597
MPTEMP,7,-12.177
MPTEMP,8,-10.565
MPTEMP,9,-8.9516
MPTEMP,10,-7.6613
MPTEMP,11,-6.2097
MPTEMP,12,-4.9194
MPTEMP,13,-3.7903
MPTEMP,14,-2.8226
MPTEMP,15,-1.8548
MPTEMP,16,-1.0484
MPTEMP,17,-0.40323
MPTEMP,18,0

UIMP,1,REFT,,,0

MPDATA,ALPX,1,,2.32E-05
MPDATA,ALPX,1,,3.25E-05
MPDATA,ALPX,1,,4.17E-05
MPDATA,ALPX,1,,5.10E-05
MPDATA,ALPX,1,,-6.03E-05
MPDATA,ALPX,1,,-0.00017152
MPDATA,ALPX,1,,-0.00032914
MPDATA,ALPX,1,,-0.00048675
MPDATA,ALPX,1,,-0.00070927
MPDATA,ALPX,1,,-0.0010245
MPDATA,ALPX,1,,-0.0014695
MPDATA,ALPX,1,,-0.0019887
MPDATA,ALPX,1,,-0.0026563
MPDATA,ALPX,1,,-0.0034444
MPDATA,ALPX,1,,-0.0043808
MPDATA,ALPX,1,,-0.0053914
MPDATA,ALPX,1,,-0.0062629
MPDATA,ALPX,1,,-0.0069167

lsel,s,line,,3
nsll,s,1
cp,7,uy,all
allsel

lsel,s,line,,4
nsll,s,1
cp,8,ux,all
allsel

lsel,s,line,,2
nsll,s,1
cp,9,ux,all
allsel

finish

/solu
antype,static
!DL,1,,UY,0,1
DL,1,,SYMM  

tref,0
outres,basic,all
physics,write,struc
finish

*do,i,1,ftime/tinc
        time0=time0+tinc
        *if,i,eq,1,then
                physics,read,thermal
                /solu
                time,time0
                solve
                finish

                physics,read,struc
                /assign,esav,struc,esav
                /assign,emat,struc,emat
                /solu
                ldread,temp,last,,,,,rth
                solve
                finish
        *else
                physics,read,thermal
                /solu
                antype,trans,rest
                time,time0
                solve
                finish

                physics,read,struc
                /assign,esav,struc,esav
                /assign,emat,struc,emat
                /solu
                antype,static,rest
                ldread,temp,last,,,,,rth
                solve
                finish

        *endif
        /assign,esav
        /assign,emat
*enddo
finish

cookyzhao

内壁处SY

cookyzhao

升温过程中SY

cookyzhao

请版主等诸位高人指点，谢谢！