宇航单机元器件随机振动疲劳分析

Fatigue Analysis of Aerospace Electronic Equipments under Random Vibration

摘要: 宇航单机在生命周期内要经历各种振动环境，在随机振动过程中，单机内的敏感元器件容易疲劳破坏而出现管脚断裂或焊点脱落。文章针对某型号宇航单机元器件管脚断裂情况，对其结构及元器件的几何模型进行了详细的有限元分析，获得随机振动工况下的均方根应力场，应用Miner疲劳损伤累计理论及三带宽技术，进行元器件管脚的疲劳分析，并对结构进行优化，再次分析得知结构改进后单机的疲劳安全裕度得到很大提高且通过了试验验证。结果表明了该疲劳分析方法的有效性。

Abstract: The aerospace electronic equipment undergoes a variety of vibration environments throughout its life cycle. In the process of random vibration, the sensitive chips in the electronic equipment are prone to fatigue failure, and the fracture of the pins or the welding joints are broken out. In this paper, the fracture of the pin of the aerospace electronic equipment is discussed, and a de-tailed finite element analysis of the geometric model of the equipment structure and chips is car-ried out to obtain RMS stress field under random vibration conditions, and Miner’s cumulative fatigue damage theory and three bandwidth technique are used to analyze the fatigue of chips and its pins. After the structure optimization of the equipment, a detailed finite element analysis of the geometric model of the equipment structure and chips showed that the optimized structure safety margin has been greatly improved and verified by test. The results show that this method is an effective method for random vibration fatigue analysis of the aerospace electronic equipment.