基于竞争失效模式的数控机床可靠性建模

数控机床是复杂的机电一体化系统，其故障不仅包括由于机械磨损造成的性能退化失效，还包括电子器件等引起的突发性失效，数控机床故障是退化失效和突发失效竞争的结果. 故本文假设突发失效和退化失效相互独立并且都服从Weibull分布，综合考虑突发失效和性能退化之间的相关性和竞争关系进行数控机床可靠性建模研究. 采用最小二乘估计法估计模型参数，运用D检验法进行参数拟和性检验；得出了一种基于竞争失效模式分析的可靠性评估模型. 最后，以15台某系列数控机床60个故障数据对该方法进行验证，说明了该方法的有效性和可行性.

Numerically-controlled machine reliability modeling based on competing failure mode

The numerically-controlled machine is a complicated electromechanical integration system, the failure mode of it includes not only performance degradation that caused by mechanical wear, but traumatic failure that is due to electronic device, and the failure of CNC is the result of competition between degradation failure and traumatic failure. So the paper assumed that the traumatic and degradation failure are independent and obey numerically-controlled machine Weibull distribution. Comprehensively considering the dependence and competitive relationship between the traumatic failure and performance degradation, the CNC reliability mode is studied. The model parameters are estimated with least-squares estimation, the model parameters fitting inspection are tested by correlation coefficient method and the reliability assessment model based on competing failure mode analysis is obtained. In conclusion, a case study of 15 CNC with 60 failures is given to valid the method, the results verify the effectiveness and the feasibility of the method.