基于威布尔分布的汽车零部件可靠性分析

Reliability Analysis of Auto Parts Based on Weibull Distribution

威布尔分布是一种连续概率分布,是可靠性工程领域中较为重要的寿命统计分布函数。文中基于三参数威布尔分布函数的数学模型,分析不同参数β,γ,η对概率密度函数的影响;研究了汽车产品可靠度R(t)和失效率λ(t)随时间变化的关系,并基于浴盆曲线探讨了不同阶段的失效原因及形式;从设计验证角度出发探讨了可靠度R、置信度C和样本容量N之间的关系,同时基于某上市车型的售后数据研究了其使用时间、故障增长数与累积故障率之间的关系。结果表明:汽车产品的可靠度R(t)随着使用时间的增加而不断降低,且随着时间的持续增加,降低速度趋缓;汽车产品的失效率λ(t)随着时间的增加,其增加速度先快后慢;在产品偶然失效期内的车辆控制器的可靠度相对早期失效期的要高。

Weibull distribution is a continuous probability distribution, which is an important statistical distribution function of life in the field of reliability engineering. Based on the mathematical model of the three-parameter Weibull distribution function, the influence of different parameters β,γ,η on the probability density function was analyzed. The relationship between the reliability R(t) and failure rate λ(t) of auto products over time was studied, and the causes and forms of failure in different stages were discussed in accordance with the bathtub curve. From the perspective of design verification, the correlation between reliability R, confidence C and sample size N was discussed.With the after-sales data of a listed model, the relationship between its use time, the number of failures and the cumulative failure rate was studied simultaneously. The results show that the reliability R(t) of auto products decreases with the increase of service time, and the reduction speed slows down with the continuous increase of time. With the increase of time, the failure rate λ(t) of auto products increases first and then slowly. The reliability of the vehicle controller in the accidental failure period of the product is higher than that in the early failure period.