Dear Calculix users
i am submitting here a problem that i can not solve properly in Calculix (2.20, Windows).
I am using the Norton Bailey creep law within a VISCO step (no time dependence), after elastic and plastic definitions.
I am trying to reproduce experimental creep data, with the main goal being to correctly predict the time up to a creep strain of 0.01.
The simulation involves a single hexaedral element of edge size 1mm, all BCs are correctly defined, and the reference ‘constant’ stress is imposed via a node force and an equation to link the master node to the slave nodes of the face on which i apply a traction.
When i define the creep parameters of the material at a single temperature, ie the reference temperature set in initial conditions, the results are perfect and as expected.
When i define temperature dependent creep parameters, even if the previously mentionned creep parameters definition point is in the list, the results are totally off. I assume this has something to so with some interpolation or fitting ?
Any idea on that ?
My final goal is to use this Norton law in a part with a temperature map and a complex stress distribution. But because of the inconsistency, i can not.
Thank you in advance for your help !
Regards
Frederic