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Taking the transmission gear of heavy equipment as the research object, the fatigue crack propagation and fatigue fracture of gear

The model used for the numerical simulation of gear bending fatigue is the same as that used in the bending

When testing the bending fatigue of 42CrMo heavy equipment transmission gear by experimental method, the data results have obvious advantages,

Before the formal bending fatigue test, the load level of the test needs to be determined. Pick two from the

The bending fatigue characteristic curve and bending fatigue limit stress of the test gear shall be combined according to different

The transmission gear of heavy equipment used in the bending fatigue test is designed based on the gear applied in

The test adopts the form of single tooth loading. It is necessary to design special fixtures according to the standard

The stress ratio r = 0.6, the number of cycles n corresponding to the stress intensity factor at the crack

In order to verify the correctness of the above crack propagation, the crack length and crack tip stress intensity factor

The dynamic continuous growth of fatigue crack is realized by resetting the crack length each time. In the numerical simulation

Fig. 1 shows 150, 300, 500 and 1000 times SEM images of fatigue fracture in the instantaneous fracture zone. The

Under the continuous loading of cyclic loading and unloading, the slip band around the crack tip deforms, resulting in the

It can be seen that the fracture clearly presents three regions with different morphological characteristics, as shown in Figure 1.

The morphological characteristics of fracture reflect the quality of materials and play an important role in material quality inspection, fault

Under the action of cyclic load, cracks begin to appear and grow, and the remaining life of the sample is

By referring to the national standard GB / t6398-2000 test method for fatigue crack growth rate of metallic materials, the

The fatigue crack evolution test and numerical simulation of transmission gears of heavy equipment are studied. The preparation of compact

The transmission gear of heavy equipment has low rotation speed in the process of transmission operation, but needs to bear

J. Kmmberger proposed that it is necessary to carry out anti fatigue design for mechanical components bearing periodic load. Therefore,

Robert Basan proposed a mathematical model of slip line contact and a multiaxial fatigue life calculation model based on Fatemi

He Xiaohua of Chongqing University analyzed and studied the bending fatigue strength of 20CrMoH gear. Combined with mathematical statistics theory

At present, the research of gear bending fatigue reliability test mainly focuses on how to improve the bearing capacity of

The research on the method of compound mode crack propagation is mainly through numerical simulation and experimental research. For the

Yang carried out a series of fatigue tests on C45 steel samples with local surface cracks. The effects of carburizing

Due to the importance of small fatigue cracks, many researchers at home and abroad have carried out extensive research on

Different types of cracks have their own stress and displacement: type 1 crack is subjected to tensile stress perpendicular to

The whole fatigue process includes three stages: crack initiation, crack propagation and fracture failure caused by final instability propagation. The