基于可靠性分析的太阳电池阵驱动弹簧设计

Reliability-based design of the drive spring of a solar array

以太阳电池阵驱动弹簧为研究对象,建立动态可靠性模型,并提出太阳电池阵驱动弹簧的可靠性优化设计方法。在建立动态可靠性模型过程中,假设载荷历程为Poisson过程,并考虑驱动弹簧参数的变化对应力及强度分布的影响。通过灵敏度分析,提出基于动态可靠性模型的优化设计方法。算例研究表明:即使在强度不退化的情况下,驱动弹簧的可靠度仍然随着时间的增加而降低。同时,失效率曲线与偶然失效期浴盆曲线相一致。此外,基于传统应力-强度干涉模型的可靠性优化方法可能由于忽略了可靠性的动态特性而使设计结果具有较高危险性。

A dynamic reliability model was developed for the drive springs of a solar array with reliability based optimization used to design the springs. The dynamic reliability model assumes that the loads are a Poisson process. The model also accounts for the influences of the variations of the drive spring parameters on the distributions of both the load and the strength. The optimization design method is based on the dynamic reliability model and a sensitivity analysis. A case study shows that the drive spring reliability decreases with time even when the strength remains constant. The failure rate curve is consistent with the bathtub curve in the random failure period. Optimization using the conventional stress strength interference model can be dangerous since it neglects the dynamic characteristics of the reliability.