机载雷达结构随机振动疲劳破坏技术研究

Study on Destruction from Vibration of Airborne Radar Structure

振动疲劳破坏潜在巨大威胁,是航空结构破坏的一种主要形式。快速准确地预测结构随机振动条件下的薄弱环节是结构设计的关键技术之一。文中将有限元分析与振动试验进行了对比分析,对结构疲劳破坏的机理进行了探究,分析了模态振型与随机振动破坏的内在联系。除定性判断外,还引入了基于PSD的疲劳寿命分析理论方法,将MSC软件与当前流行的疲劳分析软件结合起来,对某分机安装架进行了疲劳寿命分析计算,分析结果与试验吻合度良好。对结构疲劳破坏规律的研究,为后续结构设计分析提供了理论支撑。

As one of the primary form of the aviation structure destruction, the destruction from vibration fatigue has huge patential threat. Forecasting the weakness fleetly and accurately in structure random vibration is one of the key technologies for structure design. This paper compares the analysis result of finite element and the vibration experiment result, explores the theory of the structure fatigue destruction and analyses the imma- nent relationship of mode vibration format and random vibration destruction. Besides, an analysis method for fatigue life based on PSD is also introduced. With MSC software combined with the popular fatigue analysis software, fatigue life analysis and calculation for a fixing shelf are carried out. The analysis result agrees with the experiment result. Study on the structure fatigue destruction rule supports in theory the subsequent struc- ture design and analysis.