以载荷作用次数为寿命指标的失效相关系统可靠性建模  

Reliability Modeling of Systems with Dependent Failure when the Life Measured by the Number of Loadings

作　　者：王正[1] 康锐[1] 谢里阳[2] 

机构地区：[1]北京航空航天大学可靠性工程研究所,北京100191 [2]东北大学机械工程与自动化学院,沈阳110004

出　　处：《机械工程学报》2010年第6期188-194,共7页Journal of Mechanical Engineering

基　　金：中国博士后科学基金(20080440294;200902042);国家自然科学基金(50905007)资助项目

摘　　要：提出以随机载荷作用次数为寿命度量指标框架下的失效相关系统可靠性建模方法。考虑系统中各零部件之间存在的失效相关性,通过引入条件可靠度建立失效相关系统可靠性模型。分别以静强度失效和疲劳失效的可靠性分析为背景,给出强度不退化和强度退化时随机载荷多次作用下的系统可靠度与失效率计算模型,并研究系统可靠度与失效率随载荷作用次数的变化规律。研究表明,即使强度不退化,系统的可靠度和失效率也会随着随机载荷作用次数的增加而逐渐减小,失效率曲线具有浴盆曲线'早期失效期'和'偶然失效期'的特征。强度随载荷作用次数退化时,随着载荷作用次数的增加,系统的可靠度降低较为明显;失效率先减小后增大,具有'浴盆曲线'的特征。所建立的模型可用于指导系统的可靠性设计、可靠性试验和全生命周期管理。The method for modeling reliability of systems with dependent failure when the life is measured by the number of loadings is developed. Dependent failure existing among components is considered, and reliability models of systems with dependent failure are derived through introducing the conditional reliability of systems. Taking the analysis of static strength failure and fatigue failure as the backgrounds, the models for calculating the reliability and failure rate of systems under repeated random load without strength degeneration and those with strength degeneration are derived respectively. Then, the relationship between the reliability of systems and the number of loadings, and that between the failure rate of systems and the number of loadings are discussed in different cases. The result shows that even though strength doesn＇t degenerate, both reliability and the failure rate of systems decrease as the number of loadings increases, and the failure rate curves have the partial characteristics of bathtub curve with early failure period and random failure period. When strength degenerates with the number of loadings, the reliability of systems decreases more obviously as the number of loadings, and the failure rate of systems decreases first and then increases as the number of loadings, showing the whole shape of bathtub curve. The models proposed can be applied to guiding the reliability design, reliability test and the whole lifecyele management of systems.

关 键 词：系统可靠性 载荷作用次数 失效相关 可靠度 失效率 浴盆曲线 

分 类 号：TB114.3[理学—概率论与数理统计] TH122[理学—数学]