动车组产品可靠性评估与验证

In light of the different characteristics of EMUs, components and other products, according to the classification evaluation principle of different models, different products, different operation conditions, different failure consequences, different confidence requirements and so on, the reliability evaluation methods of EMU products were studied, including the evaluation method of lower confidence limit of reliability and the evaluation method of the upper confidence limit of failure rate. To improve the verification efficiency and benefit, from the principle of the minimum verification samples, the shortest verification time and the lowest verification cost, the verification method of EMU reliability and failure rate under failure-free condition was studied. Examples were used to evaluate and verify the EMU failure rate and the reliability of axle box bearing. Results show that: by using the evaluation and verification method, the number of samples required for test verification can be obtained when the confidence levels of EMU products are 50%, 90%, 95% and 99% respectively, and the lower limits of product reliability are 0.9-0.99 and 0.991-0.999 respectively, as well as the accumulated test verification mileage required when the upper limit of failure rate per million km is 0.1-1.0 respectively, so as to realize the quantitative assessment and verification assessment based on reliability target requirements.