基于退化失效模型的旋转机械寿命预测方法

退化失效模型与传统可靠性预测的根本区别在于,不论在统计推断还是寿命分布拟合过程中,可以充分利用退化数据提供的更多过程和寿命信息,能较准确地进行具有耗损特性的机械产品的寿命预测.针对旋转机械运行过程中强度破损失效模式,本文利用正态随机过程模型描述其退化失效过程,进行了旋转机械的寿命预测方法研究.通过分析加速寿命方程与退化失效模型的关系,考虑到加速寿命试验方法以"应力换时间"的有效性,进行了旋转机械加速寿命试验.通过对试验结果进行最佳线性无偏估计,得到强度退化失效模型的退化轨迹;在解决了退化失效方程奇异性的基础上,进行了旋转机械的寿命预测,得到点估计与区间估计的可靠寿命预测结果.

Degradation model and application in life prediction of rotating-mechanism

The degradation data can provide additional information beyond that provided by the failure observations, both sets of observations need to be considered when doing inference on the statistical parameters of the product and system lifetime distributions. By the degradation model showing the wear out failure, the predicted results of mechanism life is more accurate. Strength is one of the important capabilities of the rotating mechanism. In this paper, the degradation data of strength are described as a stochastic process model. Accelerated tests expose the products to greater environmental stress levels so that we can obtain lifetime & degradation measurements in a more timely fashion. Using the Best Linear Unbiased Estimation (BLUE) Method,the parameters under the degradation path were estimated from the accelerated life test (ALT) data of the rotating mechanism. Based on solving the singularity of degradation equation, at any time the reliability is estimated by the using the strength-stress interference theory. So we can predict the life of the rotating mechanism.