【作者】 张华；

【导师】 吴斌；

【作者基本信息】 西北工业大学 ， 飞行器设计， 2007， 硕士

【摘要】 在装卸、运输和发射、飞行的过程中，飞行器要经历复杂的力学环境，以振动和冲击环境最为典型。振动引起的破坏是飞行器服役过程中发生故障的主要因素之一，许多飞行器载机械和电子设备的故障和飞行事故都与振动问题直接或间接有关。振动和冲击均会造成飞行器结构和其上设备的疲劳失效，是影响疲劳寿命的重要因素，疲劳寿命是可靠性的重要指标。 本文将依托成熟的计算机仿真技术，对飞行器结构力学环境的模拟方法进行仿真研究，并探讨这一研究对飞行器结构力学环境的试验模拟方法指导的指导作用。本文的主要研究内容和结论有： 1．对插装型电子元器件建立了有限元模型，并分析其动态响应，还分析了一定范围内的结构误差不会对系统动态特性产生较大影响；通过分析系统的动态特性，发现元器件对低频载荷比较敏感，可靠性强化试验宜针对低频段加载；同时，通过应力分析，揭示了电子元器件因管脚断裂而失效是由振动时引线中的弯曲应力引起的； 2．对插装型电子元器件建立了非线性有限元模型，计算了模型在冲击载荷下的时域响应；通过应力分析，揭示了电子元器件因管脚断裂而失效是由冲击时引线中的径向应力引起的； 3．基于随机振动疲劳理论在线弹性条件下对插装型电子元器件预测了疲劳寿命；针对强化试验中大量存在的塑性问题以及现有振动疲劳理论只能处理线弹性问题的局限性，本文提出将塑性等效为阻尼的方法；此外，仿真寿命结果可指导可靠性强化试验剖面的设计； 4．对一般疲劳理论进行了修正，使其适用于冲击疲劳理论，计算了弹塑性条件下插装型电子元器件的冲击疲劳寿命； 5．对摆锤式冲击响应谱试验台进行了仿真研究，模拟了飞行器爆炸冲击环境；得出了冲击响应谱与仿真参数的关系并模拟了一系列冲击响应谱规范。 本文以有限元理论、信号处理方法、弹塑性动力学、疲劳理论为基础，建立了一套计算机仿真技术应用于疲劳寿命试验技术的方法；仿真得出了摆锤式冲击更多还原

【Abstract】 In the process of handling, transport, launch and flying, the space vehicles are always in the complex environment of mechanics, for example, the vibration and impact are the important influence.The vibration of the vehicles is one of the most important factors which cause trouble in the vehicles’flying. The out of order of mechanical and electrical system on the space vehicles and flying accident are both effected directly or indirectly by vibration. The vibration and impact will both cause fatigue failure of the structure and system, which is a very important factor about fatigue life. And fatigue life is an Important index of the reliability.The computer emulation is used in this research to simulink the analogy method of the environment of dynamics of space vehicles structure. And the guidance function of the method is also discuseed. The main research and conclusion are as follow:1. a finite element analysis model of the plug in electrical parts is built and-dynamic response is analyzed. Then the error of the structurein some range doesn’t cause big effect to the dynamic characteristic of the structure is also validated. By analyzing the dynamic characteristic of the system , it is found that the parts are sensitive to payload of low-frequency and the experiment of reinforcing reliability is suitable for loading in the low frequency. At the same time, by stress analysis, it shows that the failure of the electrical parts which is because of the abruption of the base pin is caused by the bending stress in the pins. And the stress is also caused by the vibration.2. a nonlinear finite element analysis model of the plug in electrical parts is built. Then the time domain response of the model under the impulsive load is computed. And by analyzing the stress, it shows that the failure of the electrical parts which is because of the abruption of the base pin is caused by the radial stress in the pins. And the stress is also caused by the vibration.3.Based on the theory of vibration fatigue, the fatigue life of the plug in electrical parts is predicted. In order to solve the plastic problem which exists in the experiment of reinforcing and the limit of the theory of vibration fatigue which only be used in the linear elasticity, a method of equaling the elasticity with damping is developed. Furthermore, the simulation result of the life can be used to guide the design of the更多还原