i would like to simulate a tensile test under stress-controlled loading and to compare numerical results to experiments.
Experimentally, i have imposed the form of this cycle (figure):
loading sequence: load up 4kN, 1mm/min
unloading sequence: unloading with a displacement -1mm/min
so my unloading sequence is not under load control (it is impossible with our tensile machine).
How can i simulate this test under stress-controlled loading?what is the form of my loading-unloading sequence?