Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

ANSYS Coupled field analysis

Status
Not open for further replies.

hiwiansys

Mechanical
May 4, 2007
23
Hi All,

I am doing a coupled field analysis(Structural-Thermal) in ANSYS 11.I face certain problems.I request your suggestions regarding the same.

Error Message obtained while running an analysis:

The Error message I got said ''equivalent plastic strain increment has exceeded the specified limit value.Since the time increment has reached the minimum value,the analysis is stopped''.

Problems faced:Result obtained not correct.

Thermal Load data is applied cyclic,I mean 2 secs of Temperature load and 300 secs of cooling applied through second input file.So Stress should increase when model is in cooling cycle.But in my model,stress doesn't vary,it never decreases at any time.do not know why.Please give me some hints why does stress value never drops down in this analysis?

The 3 materials used are Material 1 corresponds to Ceramic,second material to solder and 3 material to steel part.

INPUT FILE:





/BATCH
/BEGIN
!* 0. CONTROL PARAMETER
!*
*set, R1, 7.5e-3
*set, R2, 18.5e-3
*set, h1, 13.55e-3
*set, h2, 4.5e-3
*set, h3, 0.5e-3
*set, h4, 15e-3
*set, N, 3
*set, factor, 1.0
*set, n_h1, nint(factor*N*h1/h3)
*set, n_h2, nint(factor*N*h2/h3)
*set, n_h4, nint(factor*N*h4/h3)
*set, n_R1, nint(N*(R2-R1)/h3)
*set, n_R2, nint(N*R2/h3)
*set, eps_s, 0.0010*h3/N
*set, eps_t, 0.0001*h3/N
*set,TREF,20

*set, NSS, 20
*set, NSSMAX, 100
*set, NSSMIN, 10

FINISH!*
!* 2. GEOMETRY & ELEMENT
!*
/PREP7
!*
ET,1,PLANE13,4,,1
!*
k,1,0,0,0
k,2,R2,0,0
k,3,R2,h4,0
k,4,0,h4,0
k,5,R2,h4+h3,0
k,6,0,h4+h3,0
k,7,0,h4+h3+h2,0
k,8,r2,h4+h3+h2,0
k,9,r2,h4+h3+h2+h1,0
k,10,r1,h4+h3+h2+h1,0
k,11,r1,h4+h3+h2,0
!*

a,1,2,3,4
a,4,3,5,6
a,6,5,8,7
a,11,8,9,10
aadd,3,4

!*
!* ENDOF 2
!*
!* 3. MESHPARAMETER
!*
lesize, 1,,,n_R2,,,,,0
lesize, 2,,,n_h4,factor,,,,0
lesize, 3,,,n_R2,,,,,0
lesize, 4,,,n_h4,1/factor,,,,0
lesize, 5,,,N,,,,,0
lesize, 6,,,n_R2,,,,,0
lesize, 7,,,N,,,,,0
lesize, 8,,,n_h2,1/factor,,,,0
lesize, 10,,,n_h2,factor,,,,0
lesize, 12,,,n_h1,1,,,,0
lesize, 13,,,n_R1,1,,,,0
lesize, 14,,,n_h1,1,,,,0
lesize, 15,,,(n_R2-n_R1),,,,,0

!*

!* 1. MATERIAL PARAMETER
!*
!------------------------
!------------------------
*set, ro_stahl, 9900
!------------------------
*set, ex_stahl, 1.8e11
*set, nuxy_stahl, 0.3
*set, ctex_stahl, 11.7e-6

!------------------------
*set, c_stahl, 460
*set, kxx_stahl, 26
*set, emis_stahl, 0.0
!------------------------
!------------------------
*set, ro_lot, 7700
!------------------------
*set, ex_lot, 0.94e11
*set, nuxy_lot, 0.3
*set, ctex_lot, 18.0e-6


!------------------------
*set, c_lot, 185
*set, kxx_lot, 25
*set, emis_lot, 0.0
!------------------------
!------------------------
*set, ro_keramik, 3240
!------------------------
*set, ex_keramik, 2.9e11
*set, nuxy_keramik, 0.18
*set, ctex_keramik, 8.4e-6

!------------------------
*set, c_keramik, 662
*set, kxx_keramik, 35

*set, emis_keramik, 0.0
!------------------------
!------------------------
!*

!* 4. ADJUSTMENTs FOR MATERIAL PROPERTY
!*
!------------------------
mp, dens, 3, ro_stahl
mp, ex, 3, ex_stahl
mp, nuxy, 3, nuxy_stahl
mp, ctex, 3, ctex_stahl
mp, c, 3, c_stahl
mp, kxx, 3, kxx_stahl
mp, emis, 3, emis_stahl
!------------------------
mp, dens, 2, ro_lot
mp, ex, 2, ex_lot
mp, nuxy, 2, nuxy_lot
mp, ctex, 2, ctex_lot
mp, c, 2, c_lot
mp, kxx, 2, kxx_lot
mp, emis, 2, emis_lot
!------------------------
mp, dens, 1, ro_keramik
mp, ex, 1, ex_keramik
mp, nuxy, 1, nuxy_keramik
mp, ctex, 1, ctex_keramik
mp, c, 1, c_keramik
mp, kxx, 1, kxx_keramik
mp, emis, 1, emis_keramik
!------------------------

mptemp, 1, 20, 100, 200, 300
mptemp, 5, 400, 500, 700
tb, bkin, 2, 6
tbtemp, 20
tbdata, 1, 320E6, 0
tbtemp, 200
tbdata, 1, 300E6, 0
tbtemp, 300
tbdata, 1, 285E6, 0
tbtemp, 400
tbdata, 1, 260E6, 0
tbtemp, 500
tbdata, 1, 160E6, 0
tbtemp, 700
tbdata, 1, 20E6, 0
!*
!* ENDOF 4


!* 5. MESHING
!*
mshape,0,2D
mshkey,0
mat, 1
amesh,5
mat, 2
amesh,2
mat, 3
amesh,1

/SOLU
/SOLU

!* 7.1 BOUNDARY-, INITIAL-, LAST CONDITIONS & SOLVE
!*
lsel, s, loc, x, -eps_s, +eps_s, , 0
dl, all, , symm, , 1
allsell, all
ksel, s, loc, x, -eps_s, +eps_s, , 0
ksel, r, loc, y, -eps_s, +eps_s, , 0
ksel, r, loc, z, -eps_s, +eps_s, , 0
dk, all, , 0, ,1, all
allsell, all


EQSLV,ITER,4
outres,all,all


!*6.1 Soldering Temperature Condtions
!*
Antype,trans
tunif,20
autots,on

*set, temperature1, 500.0

sfl,2,conv,25,,temperature1 ! since line 1 is the bottom line.it is subjected to adiabatic heating condition.
sfl,5,conv,25,,temperature1
sfl,8,conv,35,,temperature1
sfl,12,conv,35,,temperature1
sfl,13,conv,35,,temperature1
sfl,14,conv,55,,temperature1
sfl,15,conv,35,,temperature1
nsubst,30,60,20
kbc,0
time,3600
outres,all,all
allsel,all
solve



time,7200
kbc,0
nsubst,20,50,10
outres,all,all
allsel,all
solve


sfl,2,conv,25,,750
sfl,5,conv,25,,750
sfl,8,conv,35,,750
sfl,12,conv,35,,750
sfl,13,conv,35,,750
sfl,14,conv,55,,750
sfl,15,conv,35,,750
nsubst,20,50,10
kbc,0
time,8700
outres,all,all
allsel,all
solve

time,8820
kbc,0
nsubst,20,50,10
outres,all,all
allsel,all
solve


sfl,2,conv,25,,930
sfl,5,conv,25,,930
sfl,8,conv,35,,930
sfl,12,conv,35,,930
sfl,13,conv,35,,930
sfl,14,conv,55,,930
sfl,15,conv,35,,930
nsubst,20,50,10
kbc,0
time,9960
outres,all,all
allsel,all
solve

time,10260
kbc,0
nsubst,20,50,10
outres,all,all
allsel,all
solve


sfl,2,conv,25,,750
sfl,5,conv,25,,750
sfl,8,conv,35,,750
sfl,12,conv,35,,750
sfl,13,conv,35,,750
sfl,14,conv,55,,750
sfl,15,conv,35,,750
nsubst,20,50,10
kbc,0
time,12540
outres,all,all
allsel,all
solve



sfl,2,conv,25,,20
sfl,5,conv,25,,20
sfl,8,conv,35,,20
sfl,12,conv,35,,20
sfl,13,conv,35,,20
sfl,14,conv,55,,20
sfl,15,conv,35,,20
nsubst,20,50,10
kbc,0
time,16140
outres,all,all
allsel,all
solve


endtime=16140
KBC,0 ! STEP BOUNDARY CONDITIONS
DELTIM,100 ! MINIMUM TIME STEP
TIME,endtime ! TIME AT END OF TRANSIENT
OUTRES,all,ALL



!* 6.2 Thermal Load conditions

AUTOTS,ON

*do,i,1,5

endtime=endtime+2
time,endtime
Deltim,0.1


dl,13,,temp,1300
dl,14,,temp,1300
dl,15,,temp,1300


SFL,2,CONV,25,,300
SFL,5,CONV,25,,300
SFL,8,CONV,35,,300
SFL,12,CONV,35,,300

solve


dldele,13,temp
dldele,14,temp
dldele,15,temp

endtime=endtime+300
time,endtime
Deltim,10

SFL,13,CONV, 35 , , 300
SFL,14,CONV, 35, , 300
SFL,15,CONV, 35 , , 300

allsel,all

solve

*enddo

solve

/Fini


Thank you

Kind Regards

Anjali
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor