Life Prediction of Outer Oil Pipe of Controllable Pitch Propeller Based on Test and Finite Element Method

In this paper, the simplified S-N curve is used to fit the full range S-N curve of the outer oil pipe considering the size factor, fatigue notch factor, surface processing factor and the effect of heat treatment on the life. Based on the linear cumulative damage theory, the fatigue test data are transformed into fatigue damage values, and the transformed fatigue damage values are verified to obey the normal distribution, thus the reliability of the full range S-N curve of the outer oil pipe is obtained. This paper simulates the test scene, establishes the finite element model of the test device, imports the full range S-N curve and other material parameters into the finite element software, loads the corresponding test load, and calculates the fatigue life. The calculation result is close to the average life of the test. Then, without changing the material parameters, the outer oil pipe is taken as the object, the fatigue life of the actual working condition is calculated, and the working life of the pipe is estimated.