基于固定任务混频的寿命相关载荷分布特性

Distribution characteristic of durability load based on fixed task frequency mixing

为了对航空发动机结构件使用可靠性进行分析,需要对基于固定任务混频的寿命相关载荷的分布特性进行研究.采用数理统计的方法根据独立同分布中心极限定理对飞行载荷的累计过程进行了研究,推导了载荷累积函数的分布,从理论上证明了基于固定任务混频的寿命相关累积载荷,随着飞行剖面的累加而趋于正态分布.给出了基于固定任务混频的寿命相关载荷的分布特性算法,采用数学试验的方法用4个算例对基于固定任务混频的飞行过程进行了模拟,从而对理论分析的结果进行了验证.分析表明载荷累积函数的变异系数随累积飞行剖面数增加而下降.

In order to evaluate operational reliability of structural components,distribution characteristic of durability load based on fixed task frequency mixing needed to be analyzed.Mathematical statistics method was used and cumulative progress of flight load was studied according to the central limiting theorem of the same distribution.Distribution function of cumulative load was deduced.It is proved that as the flight profile accumulates,distribution of durability load cumulant tends to be normal.Distribution characteristic algorithm of durability load was presented.The distribution characteristic of durability load cumulant was demonstrated by four examples of numerical simulation.Results show that relative variation coefficient decreases as the number of cumulated flight profiles increases.