零件疲劳平均失效率计算方法研究

Research on calculation method of fatigue average failure rate

摘要:

失效率和平均失效率在机械产品的可靠性研究中具有非常重要的作用,它们和平均剩余寿命都决定了结构的寿命分布和可靠度。本文基于可靠性度量的基本指标,推导了寿命分布为两参数威布尔分布时疲劳可靠性系数与可靠度的关系,提出了基于疲劳可靠性系数计算结构失效率和平均失效率的方法,并推导了相应的计算过程,形成了不同寿命度量指标下较为简便的计算方法。基于已有的整体搭接壁板结构疲劳寿命试验数据,利用本文所提方法与传统积分方法对整体搭接壁板结构进行疲劳平均失效率计算和误差分析。算例结果表明所推导的计算公式形式简单,便于计算,且具有高度准确性,对机械结构的FMECA以及维修决策的制定具有指导意义。

Abstract:

Failure rate and average failure rate play a very important role in the reliability research of mechanical products. They and average residual life determine the life distribution and reliability of structures. Based on the basic index of reliability measurement, the rela-tionship between fatigue reliability coefficient and reliability was deduced when the life distribution is two parameter Weibull distri-bution. A method for calculating the structural failure rate and average failure rate was proposed based on fatigue reliability coeffi-cient, and the corresponding calculation process was derived. Based on the existing fatigue life test data of integral lap panel structure, the proposed method and the traditional integral method are used to calculate the average failure rate and error analysis of integral lap panel structure. The results show that the formula is simple, easy to calculate, and has the characteristics of high accuracy and relia-bility. It is of great significance for FMECA and maintenance decision-making of mechanical structure.