随机振动载荷下导弹滑块疲劳寿命分析

Fatigue Life Analysis of Missile slider in Random Vibration Load

目的对某一特定型号的导弹滑块,进行结构振动疲劳寿命分析,研究其在挂飞期间随机振动载荷可能导致的疲劳破坏问题。方法首先,通过有限元对导弹的仿真模型进行前3阶模态分析。其次,为了更贴近实际的挂飞环境,进行功能振动分析,并与试验结果对比,验证仿真模型符合工程使用要求。最后,应用振动疲劳寿命分析中的经典Miner线性累计损伤理论,对导弹滑块在挂飞振动下的疲劳损伤状况和预期使用寿命进行研究和估算。结果对比有限元模拟结果与模态试验数据,两者间的误差小于10%,验证了模型的准确性。此外,挂机振动分析结果与振动试验数据具有一致性,印证了模型中所采用的阻尼参数的正确性。结论该型号导弹滑块在承受挂飞振动条件下,能够达到至少65次飞行任务,总计400 h的耐用性要求,为导弹系统的设计改进和安全性评估提供了设计理论依据。

The work aims to conduct a structural vibration fatigue life analysis on a specific model of missile sliders,and delve into the fatigue failure problem that may be caused by random vibration loads during suspension flight.Firstly,a comprehensive simplified model of the missile was analyzed for the first three modes using the finite element method.Secondly,in order to better fit the actual suspension flight and flying environment,a functional vibration analysis was conducted.The experiment results were compared to verify that the model met the requirements of engineering use.Finally,the classic Miner linear cumulative damage theory in the vibration fatigue life analysis was applied to conduct in-depth research and estimation of the fatigue damage status and predicted service life of missile sliders under suspension flight vibration.Through comparing the finite element simulation results with ground experimental data,it was found that the error between the two was less than 10%,which verified the high accuracy of the model.In addition,the analysis results of the suspension flight vibration were consistent with the independent vibration test data,confirming the correctness of the damping parameters used in the model.The missile slider of this model can achieve durability requirements of at least 65 flight missions and a total of 400 hours under suspension flight vibration conditions,providing strong theoretical basis for the design improvement and safety evaluation of missile systems.