Reliability modeling for planetary gear transmission system considering dependent failure processes

Abstract

Many mechanical systems are subject to degradation and random shock processes, which are dependent and competing. The two processes are soft failure process and hard failure process, either of which occurs will cause the system to fail. In this paper, a hard failure model of the gear system is established based on the Stress-Strength Interference model, and a soft failure model of the system is also proposed. To consider the dependence between the two failure processes, the copula function is adopted. Then, the reliability model of the system subject to degradation and shocks is developed, and an expression of the system reliability is derived. Finally, a planetary gear transmission system is taken as a numerical example to demonstrate the effectiveness of the proposed model, which is considered a k-out-of-n system experiencing the processes of degradation and random shocks. Moreover, the effect of model parameters on reliability is evaluated through sensitivity analysis.

Reliability Evaluation of Transmission Planetary Gears “bottom-up” approach

“…Reliability analysis is closely related to the concepts of the required service life of the system and unreliability. Thus, the concept of reliability has a different interpretation in each step of product design, use and product service [3,7,13,18,25].…”

“…By analyzing models of planetary gears, the authors [5] considered a large number of errors that may occur in the production process and therefore affect the functioning of planetary gears. The analysis of the dynamic model of reliability based on random lifetime [10] and disturbances [16,24], as well as the destruction process [17] by monitoring the tests whether the tests are done in laboratory conditions or in the process of explotation [12] provide good guidelines for the development of planetary gears from the aspect of its reliability. According to the available literature, a certain number of authors dealt with predicting the reliability of wind turbines [4,15,23], Helicopter Main Gearbox Lubrication System using Influence Diagrams in a way that helped to analyze and define the reliability of planetary gears.…”

Reliability assessment of a system with multi‐shock sources subject to dependent competing failure processes under phase‐type distribution

“…developed a novel reliability model with the facilitation model subject to DCFPs. Lyu et al 28 . applied dependent competing risk processes of soft and hard failure established by the stress–strength interference model to a planetary gear transmission system.…”

“…Che et al 27 developed a novel reliability model with the facilitation model subject to DCFPs. Lyu et al 28 applied dependent competing risk processes of soft and hard failure established by the stress-strength interference model to a planetary gear transmission system. Concerning expressing the arrival number of random shocks, the previous literature mainly focuses on the Poisson process.…”

“…This paper develops a reliability model for a micro-engine with multi-shock sources subject to DCFPs. The reliability function of hard failure is established by different distributions in previous works of literature, for example, normal distribution, 16,20,22 multivariate normal distribution, 37 stress-strength interference model, 28 and so forth. We use the phase-type distribution to calculate the reliability of hard failure.…”