浅谈机械产品可靠性设计和评估方法研究及应用

Research and Application of Reliability Design and Evaluation Method of Mechanical Products

文章介绍了传统的应力-强度干涉模型、多应力问题的全概率公式、正态分布的应力-强度干涉模型的可靠度计算公式及机械产品可靠性设计的一般步骤,同时对系统可靠性预测的两大类方法(统计方法和分析方法)进行了说明,列举了并联模型、串联模型、混联模型、表决模型、储备模型、次序统计量模型、极值统计量模型和应力-强度干涉模型可靠度的计算公式,重点介绍了指数分布、正态分布、对数正态分布、威布尔分布等可靠性工程中常用分布模型,研究了参数估计、分布假设检验、寿命估计等可靠性评估过程。基于某机车空调、牵引变压器运用及故障数据,应用威布尔分布对其可靠性进行了评估,计算其在指定可靠度时可靠寿命单侧置信下限及各检修周期的可靠度单侧置信下限,掌握产品可靠度随运用里程增加的变化规律,并给出相应修程修制优化建议,以保证产品可靠度满足要求。

This paper introduces the traditional stress-strength interference model,the total probability formula of multi-stress problem,the reliability calculation formula of stress-strength interference model with normal distribution and the general steps of reliability design of mechanical products.At the same time,the paper describes two kinds of methods(statistical method and analytical method)of system reliability prediction,enumerates the reliability calculation formulas of parallel model,series model,parallel-series model,voting model,reserve model,sequence statistical model,extreme value statistical model and stressstrength interference model.The distribution models commonly used in reliability engineering,such as exponential distribution,normal distribution,lognormal distribution and Weibull distribution,are emphatically introduced,and the reliability evaluation processes such as parameter estimation,distribution hypothesis test and life estimation are studied.Based on the operation and fault data of air conditioner and traction transformer of locomotive,its reliability is evaluated using Weibull distribution,and the one-side lower confidence limit of the reliability life and the one-side lower confidence limit of the reliability of each repair cycle are calculated when the reliability is specified.The variation law of the product reliability with the increase of service mileage is mastered,and the corresponding optimization suggestions for the repair process and repair system are given to ensure that the product reliability meets the requirements.