旋转对称结构零部件时变可靠性模型

分析了旋转对称结构零部件的失效特点以及对称单元数对零部件可靠性的影响,建立了能体现对称单元数的旋转对称结构零部件强度概率密度函数和累积分布函数.分别以随机载荷作用次数和时间为寿命度量指标,建立了随机载荷作用下能够全面体现载荷、强度、对称单元数、寿命指标等参数影响的旋转对称结构零部件时变可靠性模型与失效率计算模型.研究表明:在强度不退化的情况下,旋转对称结构零部件的可靠度也会随着寿命指标(载荷作用次数或时间)逐渐降低,失效率随寿命指标逐渐减小.对于具有相同对称单元的旋转对称结构零部件,随着对称单元数的增加,零部件可靠度会降低且失效率会增大.

Time-dependent reliability models of components with rotatory-symmetrical structure

The failure characteristic of components with rotatory-symmetrical structure and the effect of the number of symmetrical parts on their reliability were analyzed.The probability density function and cumulative distribution function of strength of components with rotatory-symmetrical structure were developed.Then,taking the number of load application and time as its life parameter,respectively,the time-dependent reliability models and failure rate models of components with rotatory-symmetrical structure were derived,which consist of load,strength,the number of symmetrical parts and life parameters.The results show that when strength doesn’t degenerate,the reliability of components with rotatory-symmetrical structure still decreases as the life parameter(namely,the number of load application and time),and the failure rate also decreases as the life parameter.For the components consisted of the identical symmetrical part,its reliability decreases as the number of symmetrical part increases,and its failure rate increases as the number of symmetrical part increases.