[Solved] Rubber Curing: ABAQUS UMATHT Subroutine Problem ...
I am writing a UMATHT subroutine (Abaqus) to simulate rubber curing process and predict state of cure. In this effort I used the empirical model by Kamal and Sourer. The reference is shown below.
the UMATHT code I written is mentioned below. The problem i noticed is, the state variable to show state of cure is not displaying in abaqus. When I inquired through the code, I realised the "time" parameter is not properly assigned to X (bolded in red color as shown below)
C CPu is the specific heat capacity of uncured rubber
C CPc is the specific heat capacity of cured rubber
C RATE IS THE RATE CONSTANT
C F IS THE MATERIAL CONSTANT
C A IS THE INDUCTION TIME
C Ku is the thermal conductance of uncured rubber
C Kc is the thermal conductance of cured rubber
E = PROPS(5)
R = PROPS(6)
k0 = PROPS(7)
F = PROPS(8)
N = PROPS(9)
t0 = PROPS(10)
C Calculation of Specific Heat Capacity
C Calculation of Thermal Conductivity
C Calculation of Rate Constant
C Calculation of Induction Time
C Calculation of state of cure (alpha)
alpha = G/(1-G)
DUDT = CP
DU = DUDT*DTEMP
U = U+DU
c do i=1,nstatv
c end do
Could you please help me a way to assign this value, so that this model can be run smoothly.
I used single element input file to run this code. It is attached.
Any suggestion is welcome.
Thanks a lot
I looked at your code quickly, and I seems that TIME(1) is assigned to the local variable X. What happens if you add a
print '(a,g16.6)', "X=", X
I think I see the problem. You fined alpha by:
This means alpha is a vector with length one.
I suggest that you remove alpha(1) from the DIMENSION statement. That should take care of the problem.