A reciprocating fluid dynamic seal life prediction method based on multivariate correlation degradation modeling

Abstract

The invention provides a reciprocating fluid dynamic seal service life prediction method based on multivariate correlation degradation modeling, and belongs to the field of reciprocating seal reliability evaluation and service life prediction of motion machine parts. The method comprises the steps that 1, degradation amount data of friction force and leakage amount are collected; Step 2, accordingto the distribution function of the Frank Copula, establishing a joint distribution function of the friction force degradation increment and the leakage rate degradation increment; Step 3, establishing a reciprocating seal multivariate correlation degradation model; 4, establishing a log-likelihood function of the multivariate random correlation degradation process model, and obtaining an estimation result of a parameter sum through degradation data; and 5, calculating the reliability of the reciprocating sealing element by adopting a Monte Carlo method in combination with the multivariate related degradation model, and obtaining the service life of the reciprocating sealing element. The coupling relation between the two performance degradation indexes of the friction force and the leakage rate is comprehensively considered, the sealing element degradation process model is built based on the degradation data, the calculation process is simple and convenient, flexibility is high, and engineering practice is approached.

Description

Technical field [0001] The invention belongs to the field of reliability evaluation and life prediction of reciprocating seals of moving parts, and specifically relates to a multivariate correlation degradation analysis of reciprocating seals and a modeling method for life prediction thereof. Background technique [0002] Reciprocating seal refers to the dynamic seal between reciprocating moving parts, which is widely used in hydraulic and pneumatic cylinders such as aviation, aerospace, ships, automobiles, and medical equipment. According to relevant statistics from the US military in the 1970s, 90% of aircraft actuators that must be repaired or replaced due to failures are external leakage caused by the failure of the actuator's dynamic seal. In different products, the reciprocating seal bears different working conditions, and its life span is also different. The reciprocating seal of the piston rod of the hydraulic actuator is a key component that restricts the long-life serv...

AI Technical Summary

Problems solved by technology

[0005] At present, domestic and foreign materials on reliability evaluation and life prediction of seals can be retrieved, most of which focus on the research based on physical failure mechanism models, and there are very few contents on reliability evaluation and life prediction of reciprocating seals based on degradation data

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