0

I am new to writing Abaqus user subroutines. I am trying to figure out if there is way in which I can define solution dependent variable in an Abaqus user subroutine. I am trying to implement leakoff for the cohesive element as a time dependent parameter. I am planning to use UFLUIDLEAKOFF subroutine to implement this functionality. The leakoff model is as shown below.

Leakoff=C*f(t,τ) where,C=constant t=current time τ=time at which the cohesive element was damaged

τ is a solution dependent parameter which is not defined if the cohesive elements is not damaged i.e. SDEG = 0. Thus, τ is different for each element and has to be updated for the elements which are damaged in this step, unchanged for the elements which were damaged prior to this step and should be not defined for the elements which are still intact. The leakoff in the subroutine will be computed by:

If τ is NOT defined then we have a user defined constant leakoff If τ is defined, then we compute the value of leakoff from the function f(t,τ).

I believe we can define a state variable associated with the cohesive elements and then somehow read that in the user subroutine and choose the leakoff value based on that.

I would appreciate any help in this matter. Thanks.

user3744995
  • 11
  • 2

1 Answers1

1

A state variable or SVAR is definitely the best approach. The number of SVARS you need though is dependent upon the element type and how many variables you need to keep track off during each time increment.

For instance if you have a four node element and you need to keep track of three variables during each time increment then you will have 12 SVARS for each element.

Intrepid Traveller
  • 95
  • 6