Meshing and dynamic characteristics analysis of spalled gear systems: A theoretical and experimental study

•Realistic spalling geometries are obtained from fatigue experiments.•The mesh stiffness and contact stress are verified by the finite element method.•Dynamic behaviors of the single and multiple teeth spallings are discussed.•Simulated fault features are verified by that obtained from the experiment. Considering the realistic spalling morphology obtained from the fatigue experiment, a novel dynamic model for spalled gear pairs is established in this paper. Loaded tooth contact analysis method is utilized to evaluate the meshing characteristics of spalled gear pairs. In order to verify the proposed method, the mesh stiffness and contact stress obtained from the proposed method are compared with those obtained from the finite element method and the method in published literature. The mesh stiffness and the non-loaded static transmission error are imported into the geared rotor dynamic model to acquire the dynamic responses. The spectrum characteristics and statistical indicators under different spalling patterns are acquired by the proposed model. A comparison between simulation and experiment is performed to verify the proposed dynamic model. The results show that the simulated fault features agree well with that obtained from the experiment, which indicates that the proposed model is a promising tool for the fault mechanism study of gears with realistic spalling patterns.