Wear reliability analysis of tapered valve based on second moment of checking point

基于验算点二阶矩的锥形活门磨损可靠性分析方法

¹ AVIC China Aero-Polytechnology Establishment, Beijing 100028, China
² School of Construction Machinery, Chang'an University, Xi'an 710064, China
³ Beijing Power Machinery Institute, Beijing 100074, China

Received: 7 December 2023

Abstract

In order to clarify the influence of the wear characteristics on the reliability of the conical valve in the fuel system of an aero-engine, a second-order moment reliability analysis method based on the checking point was proposed, which focuses on the influence of the key parameters on the wear reliability of the conical valve on the basis of establishing the wear depth model of the conical valve. Combining the Archard wear model with the spool force analysis, the mapping relationship between the cumulative wear depth of the valve and the geometry, material parameters, and working condition parameters was established, and the wear function was clarified and the basic random variables were determined through the generalized stress-interference theory. Through the proposed second-order moment reliability analysis method at the check point, the wear reliability and sensitivity of a conical valve were simulated and analyzed. The simulation results show that the wear reliability is positively correlated with the material hardness of the conical valve at a certain cone angle, and increasing the diameter of the valve has a more obvious effect on the wear reliability. The wear reliability is slightly improved by increasing the number of cone angles. Moreover, the variables that have positive and negative effects on the wear reliability of the conical valve are identified through the global sensitivity analysis, and the sensitivity ranking of importance and dispersion is clarified.

摘要

为了明确航空发动机燃油系统中磨损特性对其锥形活门的可靠性影响规律, 提出了一种基于验算点的二阶矩可靠性分析方法, 重点在建立锥形活门磨损深度模型基础上分析关键参数对锥心活门磨损可靠度的影响规律。结合Archard磨损模型与阀芯受力分析, 建立活门累积磨损深度与几何尺寸、材料参数、工况参数间的映射关系, 通过广义应力-干涉理论明确磨损功能函数并确定基本随机变量。采用所提出的验算点二阶矩可靠性分析方法, 对某锥形活门磨损可靠性及灵敏度进行仿真分析。仿真结果表明: 在锥角一定时, 磨损可靠度与锥形活门材料硬度呈正相关关系, 活门直径大小对磨损可靠度影响较为明显; 增大锥角度数, 磨损可靠度将有小幅提升; 通过分析全局灵敏度确定了对锥形活门磨损可靠性产生正、负向影响的变量, 并明确了重要度和分散性的敏感性排序。