In this thesis, we studied the fatigue behavior of polymer gears under cyclic bending loads experienced by individual teeth. Cracks may develop due to material fatigue, leading to gear failure. The critical section at the tooth root, determined by a 30° tangent, was analyzed through theoretical and numerical calculations. However, in practice, the actual crack initiation location may differ due to various unaccounted factors, such as material structure, defects, and surface conditions. Our focus was on investigating the influence of crack initiation location, initial crack size, orientation, applied load magnitude, and material on crack growth at the root of polymer gears. Numerical methods and linear fracture mechanics were employed for crack simulations under various conditions.
Key findings include significant experimental data for constructing the Wöhler curve, providing essential information for gear design. Furthermore, numerical simulations confirmed the accuracy of the theoretically determined critical location. The study also revealed that the initial crack size and location have a substantial impact on the gear's service life. To enhance gear durability, design considerations should account for critical stress locations and measures should be taken to prevent or mitigate the initiation of cracks. Material optimization and regular maintenance are recommended to improve fatigue resistance and ensure optimal gear performance, thus reducing the risk of failure.
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