How to conduct fracture analysis with thermal loading in Ansys?

(Not sure if this is the correct place for this problem. I also posted the question in Fracture Mechanics Forum)

I’m new to fracture analysis, and I get a problem with the Ansys analysis process with thermal loading.

I will appreciate it if anyone could give me some comments or inputs on my Ansys commands or the process to conduct fracture analysis with thermal loading in Ansys.

The stress due to mismatch of coefficient of thermal expansion (CTE) of two materials could result in fracture. I want to calculate fracture parameters (e.g. energy release rate) under thermal loading. However, all the Ansys examples and tutorials I could find about fracture analysis use mechanical load (displacement or force). My question is how to combine the thermal stress with the fracture analysis.

I have tried to conduct a thermo-mechanical analysis first, and then used the force from the result file as input load for the fracture analysis. But my Ansys command does not work. The energy release rate is zero from the final analysis. I’m attaching my Ansys command for the analyses part below. 

Thanks!
 

My Ansys commands:

/prep7
allsel,all
tref,298 !defines the reference temperature for the thermal strain calculations

/solu
antype,static,new !specifies new transient analysis
SOLCONTROL,on,on !turn on the optimized nonlinear solver
nlgeom,on !turn on the large drformation effect
outres,all,all !controls the solution data written to the database
autots,on !specifies to use automatic time stepping or load stepping
bfunif,temp,298

! thermo-mechanical analysis
ptime=300 !define time parameter
ptemp=398 !define temp parameter
time,ptime !time at the end of the step
bfunif,temp,ptemp !temp at the end of the step
kbc,0 !ramp load
deltim,5,1,10 !specifies # of sub step
solve

finish

/prep7
! define crack tip node component
nsle
nlist
nsel,s,node,,104
nlist
cm,cracktip,node !* define crack tip node component
allsel

/solu
allsel
autots,on
ldread,force,last
time,1

cint,new,1 !* crack id
cint,type,vcct !* vcct calculation
cint,ctnc,cracktip !* crack tip node component
cint,norm,0,2
outres,all,all
outres,all,all
solve

/post1
set,last
prci,1