基于加速退化数据的某型电连接器可靠性评估

Reliability Assessment for a Certain Type of Electrical Connector Based on Accelerated Degradation Data

摘要:

某型电连接器属于高可靠性、长寿命产品,在短时间内很难获取其失效数据。为了评估其可靠性,在分析其失效机理的基础上设计了步进加速退化试验,通过分析加速退化数据外推出产品在正常工作应力水平下的可靠度函数。试验中以电连接器的接触电阻作为性能参量,选取温度作为加速应力。数据分析时,利用Wiener随机过程对样品退化进行建模。为了提高模型参数的估计精度,采用极大似然法对所有性能退化数据进行整体统计推断。外推其在工作温度下的可靠度时,针对工作温度不恒定的情况利用等效温度表示温度对该产品的综合作用效果。结果表明,提出的基于加速退化数据分析的方法实用、有效,成功实现了某型电连接器的可靠性评估,并可为其他高可靠性产品的可靠性评估工作提供借鉴。

Abstract:

Since a certain type of electrical connector belongs to the product which has high reliability and long lifetime, it is difficult to obtain failure-to-time data in short time. For assessing the reliability of the product, a step-stress accelerated degradation test was designed on the base of analyzing failure mechanism and then the reliability function at the normal use stress level was extrapolated from the accelerated degradation data. Contact resistance was taken as the performance index and temperature was used as accelerated stress at the testing. When analyzing the degradation data, Wiener process was adopted to model the degradation process. A maximum likelihood function integrating all the degradation data was established for improving the accuray of estimation. When extrapolating the reliability at the working temperature level, equivalent temperature was applied to represent the comprehensive effects of several temerature levels since the working temperature was variable. Results showed that the proposed method based on analyzing accelerated degradation data was practical and effective, it realized the reliability assessment of the electrical connector and could be extended to evaluate the reliability of other highly reliable products.