user subroutine question

[mmmbordo643]

hello,

i am running a drucker-prager cap model and need to implement a user subroutine to calculate the relative density at every increment. i have the equation for density, D=(m/V)*(1/rho), where V=h*A, A being cross sectional area of the compact and h being the distance between the top punch and the bottom. i have never done a user subroutine and cannot find any literature that helps me much. any help is greatly appreciated.

also, i am using the automatic time incrementation, but the step size is very small (total time of 8 seconds, steps range from 0.01 to 5e-05. i have changed the initial, minimum and maximum step values but the job aborts when i do that. any ideas?

Thanks so much,
Chris

 

[politec21]

Hi,
I´m also looking for help to implementate a subroutine. A have no idea to do that. Must i have a fortran compiler recognized by ABAQUS? how?
About you use the automatic time incrementation, First of all you should read the ".dat" file in order to look for the error and warnings. If your problem is the method convergence, I think that you should make the minimum time incrementation smaller than 5e-05.
If someone has found any literature that helps a subroutine implentation, any help would be appreciated.
i´m not a english speaker...so sorry about the language mistakes.
Thanks.
zaz

 

[koetue]

Hello,
take a look at
Introduction to Compitational Plasticity
from
Fionn Dunne/Nik Petrinic
Oxford

cheers
koe