基于性能退化的控制力矩陀螺寿命预测

控制力矩陀螺具有高可靠、长寿命特点,传统试验方法难以获取失效样本。但是控制力矩陀螺在轨工作期间的遥测数据中包含了很多性能退化信息,在详细分析这些数据的产生机理、影响因素和变化规律的基础上,结合已知的失效指标,选择合适的性能退化参数,针对性能退化参数建立陀螺的寿命预测模型。利用遥测数据拟合模型参数,进行趋势外推计算陀螺的预测寿命。文章最后给出了两种性能退化指标的控制力矩陀螺寿命预测实例,验证了该方法的有效性。     

Methods for Reliability Assessment under Irregular Time-Varying-Stress Degradation Testing

Degradation tests are often used to assess the reliability of products with long failure-time or few test units. Much of the previous work on reliability assessment methods has focused on constant-stress degradation test（ CSDT） and accelerated degradation test（ ADT）, mainly under the constant, step or progressive stresses. However,in actual testing environments,some stresses are difficult to control and vary with time irregularly,which are quite different from the three stresses mentioned above. In this paper a new approach was presented for reliability assessment with degradation data under irregular time-varying-stress（ ITVS）.Firstly,the conventional degradation path modeling method was improved by taking into account the influences of the variable stress on the degradation variable. Then,an example was conducted to show the effectiveness of our improved model.     

基于动态事件树的安全风险分析方法

针对系统安全分析过程中,传统静态方法的局限性和现有动态方法的侧重点不同,对动态事件树分析方法进行了研究,给出了其基本理论概念,描述了基本建模过程.以某冷却缓冲装置的安全控制为例,实现了动态事件树的建模方法,通过仿真得到了该装置随时间演化过程中的动态行为及其事故演化的路径、时间和概率等信息.分析结果验证了动态事件树分析方...