导弹模态试验中双模态现象的分析与仿真验证

Analysis and Simulation Verification of Dual⁃modal Phenomenon in Missile Modal Experiment

针对导弹模态试验中出现的主振偏角较大的“双模态”现象,采用三分段法构建了用于模拟导弹模态试验系统的壳⁃梁⁃质量⁃弹簧单元组合有限元模型。通过试验分析与仿真模拟,提出并论证了导弹模态主振偏转的主要原因是舱段间对接面连接刚度方向偏离了象限线。依据试验分析结果,提出了影响导弹模态特性的相关结论。根据仿真模拟结果,得到了主振模态偏转的两个前提性条件。从工程应用的角度,给出了模态参数的使用说明,建议了舱段对接面的设计和位置。研究结果对导弹双模态现象的规避和消弱具有一定的工程指导意义。

The dual-modes phenomenon,which means the direction of the missile modal vibration deviates great⁃ly from the quadrant direction,appears in the missile modal experiment.A combined finite element model of shell-beam-mass-spring element is constructed for simulating missile modal test system by using the three-sec⁃tion method.By the experimental analysis and simulation verification,the main reason of the dual-modes is proved.The connection stiffness direction of the joint surface between cabins deviates from the quadrant direc⁃tion.Furthermore,two conclusive cognitions affecting the missile modal characteristics are presented according to the experimental results,and two preconditions for the deviation of the modal direction from the quadrant di⁃rection are obtained with the help of simulation results.Finally,from the engineering application view point,op⁃eration instructions of modal parameters are provided,and the design and location of the joint surface between cabins are presented.Results of this paper are of great importance to the avoidance and weakening of missile du⁃al-modal phenomenon.