Numerical simulation of fatigue crack propagation in tooth root of meshing heavy duty gear

Through the bending fatigue test and corresponding numerical simulation, it is obtained that the fracture of the tooth root is the main factor affecting the bending fatigue life of the gear. The crack on the tooth root will pass through a stable propagation zone from the beginning to the fracture, and the crack will have a certain propagation law in the process of going through the propagation zone. For the prediction of gear life, it is of great significance to study the crack propagation law in the propagation zone by using the propagation finite element method.

The simulation principle of crack propagation based on extended finite element is introduced. The analysis model created according to the design parameters of heavy-duty gear is established in the finite element software ABAQUS, and the crack propagation analysis of heavy equipment transmission gear with crack is carried out. The crack propagation law under different initial crack inclination and different initial crack position is studied.

The results show that the most significant factor affecting the crack propagation trajectory is the position where the crack first appears. The closer the crack first appears to the tooth top, the closer the crack propagation trajectory direction tends to the tip of the tooth in the later stage. This chapter also studies the propagation law of the initial crack under different angles. The results show that the most severe crack propagation is when the crack inclination is 60 °, the tip displacement reaches the peak, and the crack propagation is also the most severe; Compared with the influence of the initial position of the crack on the crack trajectory, the crack propagation trajectory of the gear is basically the same under different crack inclination angles, and is less affected by the initial crack angle.

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