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This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Sven Düzel, Robert Eberlein, Hans-Jörg Dennig; Fatigue life analysis of POM gears with transient material modeling. AIP Conf. Proc. 8 May 2024; 3158 (1): 110015. https://doi.org/10.1063/5.0204543 and may be found at https://doi.org/10.1063/5.0204543., The today’s standard calculation methods for investigating the load carrying capacity of polymer gears (such as VDI 2736) are based on the same assumptions as for steel gears. Due to strongly varying material properties of polymers regarding stiffness level, nonlinearity and rate dependency, the predicted lifetimes of polymer gears are inaccurate. In the current study a rate dependent nonlinear viscoplastic finite element (FE) modelling of polyoxymethylene (POM) allows quantifying the material influences not considered by standard assumptions for metal parts. By deploying such a nonlinear material model for POM, a POMsteel gear pairing is investigated and additionally validated on a gear test rig. Different rotational speeds but constant brake torque are investigated to analyse the influence of inertia under the dynamic conditions as well as the rate depended material properties to the fatigue lifetime. An accelerated approach for a repeated transient FE modelling of the gear meshing process makes it possible to investigate critical stress and strain states over consecutive cycles, specifically focusing on tooth root breaking. It turns out that a cyclic increase of (plastic) strains occurs in the polymer gear teeth roots. Through an extrapolation of the local maximum principal strain, the strain state of the failure causing cycles can be analysed and forms the basis for a fatigue life analysis of POM gears. In combination with a strain based failure criterion the admissible number of cycles of POM gears for various rotational speeds is predicted and validated against experimental results obtained from the gear test rig.