Numerical simulation of bending fatigue of 42CrMo heavy equipment transmission gear

When testing the bending fatigue of 42CrMo heavy equipment transmission gear by experimental method, the data results have obvious advantages, such as: the data results are true, reliable and authoritative. Referring to the national standard GB / t14230-1993, the test data obtained can most truly and directly reflect the fatigue life of gears. Everything is relative and has certain shortcomings. There are also some defects in testing gear fatigue, bending and durability by test method:

1) Due to the limitations of test equipment, technicians’ operation level and some experimental data, it can not be measured accurately. For example, the test can only measure the fatigue bending life of gear teeth, but the distribution of gear tooth stress during the test can not be described directly.

2) The test is relatively affected by economic level and time factors, which requires high investment of money and time cost, and the changes of stress and strain in the gear teeth can not be directly detected by the naked eye.

In order to make up for the shortcomings and shortcomings of bending fatigue test, it is not only necessary to rely on the test level, but also need to further analyze the bending failure behavior of gear tooth fatigue. Based on the previous test data, the bending fatigue numerical simulation of transmission gear of heavy equipment is carried out by the combination of test method and numerical simulation method, It provides a new idea for the bending fatigue strength and fatigue life analysis of 42CrMo heavy equipment transmission gear.

Among many fatigue durability analysis software, with the help of FE-SAFE interface, it can be connected with ABAQUS. The fatigue analysis algorithm is advanced and the accuracy is relatively high in the industry. It belongs to the mainstream fatigue analysis software. Therefore, FE-SAFE software is selected for gear bending fatigue numerical simulation. Fe – safe has the following functions:

1) Determine where cracks will occur;

2) When it breaks;

3) Safety factor of working stress;

4) Probabilistic fatigue reliability analysis.

FE-SAFE software and finite software ABAQUS can be combined. The post-processing results of FE-SAFE can be directly input into the finite software to finally obtain the gear equivalent stress nephogram. It makes the numerical simulation method to calculate the bending fatigue life and bending fatigue strength of gears more accurate.

The bending fatigue test of gear is numerically simulated by ABAQUS, and the Mises equivalent stress nephogram of gear teeth under different load levels is obtained. The results show that the side where the fatigue crack first forms is on the tensile side of the gear, which has a more significant impact on the bending fatigue life of the gear. The logarithmic fatigue life nephogram of gear teeth under different load levels is obtained by post-processing the gear numerical simulation process with the software FE-SAFE. The comparison between the bending fatigue life calculated by the software FE-SAFE and the bending fatigue life obtained by the test shows that the test and numerical simulation results are consistent, That is, the gear bending fatigue life estimated by ABAQUS / FE-SAFE can meet the requirements.