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The aim of this work is the investigation of damage evolution of materials under single step and variable amplitude loading in tests and corresponding simulations. Approaches for fatigue lifetime and fatigue limit prediction at the mesoscopic scale incorporate microstructure and grain features. This micromechanical approach coupled with polycrystalline plasticity should be able to take into account the contribution of grain orientation, grain shape, crystallographic orientation, as well as the influence of material defects. For the purpose of studying local plastic strain accumulation and therefore fatigue behavior at higher load cycles a new test rig for SEM in-situ tension-compression testing was developed by using finite element simulation coupled with topology optimization. Oxygen free high conductivity (OFHC) polycrystalline copper material with nearly uniform grain size distribution and no preferred grain orientation was chosen for the experimental investigations within this work. A simulation model of the chosen OFHC polycrystalline copper was set up. The model incorporates crystal plasticity with randomly distributed grain orientation and nearly uniform grain size distribution to match the properties of the tested specimens. Due to the high purity of OFHC copper the influence of grain boundaries can be neglected in the first phase of simulation. First simulation results are shown.