Hello together,
probably my problem is easy to solve, but right now i am stuck.
I am currently simulating a tensile test with an nonlinear thermoplast (Polypropylen).
Due to the test-velocity of DIN EN ISO 527-1, which is 1 mm/s, I am of the opinion that I have to use a time dependet solver with a prescriped velocity.
Ive tried my best to get a right presentation of the necking and the strain. All i recieve is a direct, initially strain of around 10mm, then the tension is just rising and rising. (how it should look like: https://www.youtube.com/watch?v=6l0paZJiI-s&t=131s)
Please see my attached simulation.
In my despair ive already tried the stationary solver with a auxiliary sweep over a prescribed displacement (like its used in https://www.comsol.de/model/necking-of-an-elastoplastic-metal-bar-12607). The results are looking fine, but I am missing the velocity dependence.
I am grateful for every hint.