威布尔分布下VFD恒定应力加速寿命试验与统计分析

为了精确地估计真空荧光显示器(VFD)的可靠性寿命,节省试验测试时间,通过建立加速寿命试验模型开展了4组恒定应力加速寿命试验,采用威布尔函数描述VFD寿命分布,利用最小二乘法(LSM)估计威布尔参数,完成了试验数据的统计分析,并自行开发了寿命预测软件,确定了加速寿命方程,实现了VFD的寿命估计。数值结果表明,试验设计方案是正确可行的,VFD的寿命服从威布尔分布,其加速模型符合线性阿伦尼斯方程,每个加速应力水平下VFD的失效机理不变,精确计算出的VFD寿命对其生产厂商和技术人员具有重要的指导意义。

Constant Stress Accelerated Life Tests and Statistical Analysis for VFD under Weibull Distribution Case

In order to estimate the reliable lifetime of Vacuum Fluorescent Display (VFD)more accurately, and reduce testing time, four constant stress accelerated life tests (CSALT) were conducted by establishing accelerated life test model. The statistical analysis on test data was achieved by applying the Weibull model to describe the lifetime distribution,and Least Square Method (LSM) to estimate the Weibull parameters. Furthermore, accelerated life equation was determined and self-developed software was employed to predict the VFD lifetime. The numerical results show that test design scheme of CSALT is correct and feasible, that the VFD lifetime follows Weibull distribution, that the life-stress relationship meets linear Arrhenius equation completely, and that the VFD failure mechanism keeps constant at each temperature stress. The proposed methods and the estimated reliable lifetime of VFD can provide some significant guideline to its manufacturers and technicians.