基于多场耦合建模与Bootstrap方法的滑环可靠性评估

导电滑环作为卫星太阳电池矩阵驱动机构的核心部件，其可靠性关系到卫星寿命的长短，由于空间用滑环寿命试验费用昂贵、试验周期长、样本数据量少等特点，无法获取大样本寿命数据，利用传统大样本数据进行统计推断，从而进行可靠性评估的方法存在困难。因此提出一种基于摩擦磨损模型的可靠性评估方法，应用赫兹理论、传热学方法分别计算摩擦副磨损过程中的接触区域变化和温度变化，量化热力电多场耦合对摩擦副磨损的影响，提出基于粘着磨损的多物理场耦合磨损模型，基于该模型得到的寿命数据，运用改进Bootstrap方法得到滑环寿命分布的参数估计，最后与传统可靠性预测方法结合，得到一系列滑环可靠性指标。方法对比结果表明，改进Bootstrap方法不仅具有较高的评估精度，还具有主观性小、适用性强的特点，由该方法所得的各可靠性指标均符合工程实际，具有很强的工程应用价值。 

Reliability evaluation of slip ring based on multi-field coupling modeling and Bootstrap method

The aerospace electric slip ring is a core component of the satellite solar battery array drive assembly. Its reliability is related to the satellite life. Due to the high cost of the space slip ring life test, the long test period and the small amount of sample data, it is difficult to obtain the large-size sample life data. Thus, it is difficult to conduct reliability evaluation using traditional statistical method. In order to solve these issues above, this paper proposes a reliability evaluation method based on friction and wear model. The Hertz theory and heat transfer method are used to calculate the contact area and temperature rising in the process of the friction pair wear, respectively. The effect of thermoelectric multi-field coupling on the friction pair wear is quantified. A multi-physics coupled wear model based on adhesive wear is established. The parameters of slip ring life distribution are estimated using improved Bootstrap method with the life data obtained from the multi-physics coupled wear model. Finally, a series of slip ring reliability indicators are obtained combined with the conventional reliability prediction method. The method comparison results indicate that the improved Bootstrap method provides not only high evaluation accuracy, but also weak subjectivity and flexible applicability. The method evaluation results show that all reliability indicators obtained from the proposed method are in line with the engineering reality, which have powerful application values in practical engineering.