中文摘要：

动量轮是卫星的关键组件，直接影响卫星的可靠性和寿命。动量轮具有小子样、高可靠性、长寿命和高试验代价等特点，通常无法获得大样本的失效寿命数据，这导致其可靠性评估相当困难。失效物理分析能够从本质上解释产品的失效原因，失效物理试验中的性能退化数据可搭建产品性能和失效的桥梁。鉴于此，从失效物理分析的角度出发，对动量轮这种类型产品提出了一种基于失效物理的评估框架，并针对某型动量轮建立了基于随机阈值的Gauss—Brown失效物理模型，以该模型为基础作了可靠性评估，实例表明，该方法所获得的评估结果符合工程实际。

英文摘要：

Momentum Wheel is one of the most pivotal components of the satellite, and it affects the reliability and life of the satellite directly. It is very difficult to obtain the big sample failure-life data of the Momentum Wheel which have the characteristic of small sample ,high reliability ,long life and high test charge, so that the reliability estimation of the Momentum Wheel could hardly be achieved. The failure-physics-analysis can explain the failure reason essentially; the performance degeneration data in the failure-physics test can connect the performance of product with the failure like a bridge. Aiming at the problem, a kind of estimation frame is proposed for the product such as the Momentum Wheel from the view of the failure-physics at first, and a stochastic threshold Gauss-Brown model is established for a certain type of Momentum Wheel. The effectiveness and consistency of the method is proved by an instance analysis.