Add a new history variable to feap code

[Yaakov]

Dear FEAP TEAM & Users,

I'd like to ask some questions about how to add a history variable which is based on FEAP own codes.

for example: I want to just add a new history variable to feap plasticity umat and I modify the original feap codes as follows (e.g.):

step 1: in inmate.f, line 3084,            nh1 = nh1 + nhd*nn + 1 + 1 ! ep(ntm); ep; state; a new history variable 
step 2: in modlsd.f, line 165,              h2(7) = eps(1,1) ! for example
step 3: make clean, make install

I check the modi. codes in a benchmark test, the new history variable can't be updated (my method is not useful.....).

Would you let me know,  how can I really add a new history variable to feap own umat &  where are the errors in the modification process (step1 and step 2) ?


Warm regards,
Yaakov

 

[Prof. S. Govindjee]

If you are writing a user material (umatiX.f + umatlX.f), then the way you do this is to set n1 = 1 in umatiX.f  (in the else block).
Then in your user material (umatlX.f) you will find the history variable in hn(1) and you will return your updated values in h1(1).

If your actual plans are to edit FEAP's internal material models, then it is a bit more tricky and not recommended.

[Yaakov]

Dear Prof. S. Govindjee,

Thanks very much for your reply!

I will try to use the first method for a new history variable.

Kind regards,
Yaakov