小子样多源异种不确定信息下基于故障物理的主轴轴承寿命和可靠性评估方法

The spindle bearings are key components of an aero-engine, whose reliability and life are “weak links” for life extension and reliability improvement of nation’s aero-engines. Currently, reliability modeling under small samples, multi-source information fusion and heterogeneity uncertainty quantification, Multi-correlation failure models competition mechanism etc, are key issues need to be broken while conducting aero-engine spindle bearings’ life and reliability evaluation. This proposal planning to study reliability modeling under small samples and reveal time-varying law of quality deterioration of spindle bearings, by combining multi-source information fusion method and accelerated life testing; propose a unified uncertain quantitative method to trace the sources and transmission paths of involved information uncertainties and model uncertainties in life and reliability evaluation of spindle bearing; investigate the correlation of failure mechanism and multi-correlation failure modes competition mechanism, by means of jointing accelerated life testing, physics of failure and statistic based reliability modeling methods, to present, ultimately, a novel probabilistic failure of physical methods and accelerated life testing based spindle bearing life and reliability evaluation method. This proposal takes aero-engine spindle bearings as an example to clear the common key issues when conducting life and reliability evaluation and to provide a suite of novel theoretical and useful practical concepts and universal approaches for life estimation, usage life extension and reliability improvement of bearings.

航空发动机主轴轴承寿命短和可靠性低，是制约我国航空发动机寿命增长与可靠性提高的“薄弱环节”。然而，主轴轴承寿命和可靠性评估面临着小子样下可靠性建模、异种不确定性量化、多源信息融合与多相关模式竞争失效等关键问题亟待突破。本项目将结合多源信息融合技术和多性能加速退化试验，研究小子样下的主轴轴承可靠性建模难题，揭示主轴轴承状态劣化规律；提出囊括信息和模型不确定性的不确定性统一量化方法，追溯主轴轴承寿命和可靠性评估中多种不确定性来源与传递路径；提出将加速寿命试验、故障物理和概率化的系统可靠性建模方法相结合，研究多失效模式相关及竞争机制，最终形成基于加速寿命试验和概率故障物理方法的主轴轴承寿命和可靠性评估方法。本项目以航空发动机主轴轴承为研究对象，探讨轴承寿命和可靠性评估中的共性问题，为轴承寿命预测和可靠性增长提供新思路与普适化方法，具有重要的科学意义和工程价值。

航空发动机主轴轴承是航空发动机的核心部件之一，其安全可靠运行是发动机实现其功能的重要保证和前提。主轴轴承在高温、高速、高DN值、载荷多变、工况复杂的严酷环境下运行，一旦出现故障，将会造成灾难性后果。因此，对主轴轴承进行寿命预测和可靠性分析，对于保证航空发动机安全可靠运行、避免或减少重大事故和灾害发生至关重要，具有重要的理论意义与工程价值，本项目的研究成果为主轴轴承的寿命预测和可靠性评估提供了理论依据。以中国航发哈尔滨轴承有限公司生产的某航空发动机主轴轴承为研究对象，本项目针对其寿命和可靠性评估中小子样和多源异种不确定信息的特征，通过综合利用加速寿命试验方法、故障物理建模方法和多源信息融合技术，研究了复合工况和多失效模式竞争失效下航空发动机主轴轴承基于故障物理的寿命和可靠性评估问题，旨在量化并融合其全寿命周期内小子样、多源异种信息。明确复合工况下主轴轴承多失效模式下的耦合竞争失效行为，提出了面向多模式竞争失效的主轴轴承加速寿命试验方法。研究高置信度下主轴轴承寿命和可靠性评估的故障物理建模技术，建立了耦合多源、异种不确定信息融合与故障物理的主轴轴承寿命和可靠性评估方法。将本项目提出的方法应用于NASA航空发动机轴承剩余寿命预测中，发现融合离线的聚类数据和在线不精确的信息都可以显著提高航空发动机轴承剩余寿命预测精度。