摘要
建立了随机载荷作用下的失效相关串联系统、并联系统和k/n系统动态可靠性模型,并研究了系统可靠度和失效率随时间的变化规律。在系统层运用载荷-强度干涉模型建立了失效相关系统可靠性模型;在分析系统可靠性模型的基础上,建立了系统强度的累积分布函数和概率密度函数。运用顺序统计量理论建立了载荷多次作用时等效载荷的累积分布函数和概率密度函数,进而建立了强度不退化时载荷多次作用下的系统可靠性模型以及系统动态可靠性模型。运用概率微分方程建立了强度退化时的系统动态可靠性模型。研究了串联系统、并联系统和k/n系统可靠度和失效率随时间变化的规律。研究表明:系统与零件具有相似的特征;系统的可靠度随时间逐渐降低,k/n系统的可靠度介于串联系统和并联系统之间;强度不退化时,系统的失效率随时间逐渐减小;强度退化时,系统的失效率具有"浴盆"曲线的全部特征。
The time--dependent reliability models of series, parallel and k- out- of-n systems with dependent failure were developed, and the relationship between reliability of system and time and that between failure rate of system and time were studied. Using the load--strength interference model in system level,the reliability models of systems with dependent failure were developed. Based on the analyses of reliability models, the cumulative distribution function and probability density function of system strength were built. Then,the cumulative distribution function and probability density function of equivalent load were derived with the order statistic theory when random load acted for multiple times. Further, the reliability models of systems under random repeated load and the time--dependent reliability models of systems without strength degeneration were derived respectively. With the probability differential equation, the time-- dependent reliability models of systems were built when strength degenerates. Finally, for series, parallel and k-- out-- of-- n systems, the relationship between reliability and time and that between failure rate and time were studied. The results show that system has the similar characteristic as component. Reliability of system decreases gradually with time, and the reliability of k--out--of--n system is between that of series system and parallel system. When strength does not degenerate the failure rate of system decreases gradually; and when strength degenerates the failure rate of system has the whole feature of the bathtub curve. The reliability models proposed herein are useful for determining the time of trial run and reliable life of system and making the maintenance project for system rationally.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2008年第12期1393-1399,共7页
China Mechanical Engineering
基金
国家863高技术研究发展计划资助项目(2006AA04Z408)
国家重点基础研究发展计划资助项目(2006CB605005)
关键词
动态可靠度
失效相关
系统可靠性
可靠性模型
失效率
time-- dependent reliability
dependent failure
system reliability
reliability model
failure rate
