随机失谐星载天线振动局部化的统计特性分析
A Statistical Analysis of Vibration Localization of Space-Borne Antenna

为了研究随机失谐对星载天线结构动力学特性的影响,本文建立了径向肋天线结构的集中参数模型,基于Monte Carlo数值计算方法研究了随机失谐天线的模态局部化与受迫振动响应局部化的统计特性。研究结果表明:失谐强度增大会使结构的各阶共振频率范围变宽,从而使结构发生共振的危险机率增大;失谐强度增大或耦合刚度减小都会使结构的模态局部化程度增大,其中质量失谐对高阶模态振型影响较大,而刚度失谐对低阶模态振型影响较大;失谐限制了天线结构中振动能量的传播,适当增大径向肋间的耦合刚度会使原本限制在少数径向肋上的振动能量均匀传播到所有肋上。
In order to study the effect of random mistuning on structural dynamic characteristics of space-borne antenna, a lumped parameter model of antenna with 18 radial ribs is established, and the statistic characteristics of vibration localization of the space-borne antenna is studied based on numerical calculation method of Monte Carlo. The research results show that: the mistuning strength increase causes range of antenna resonance frequency broaden, which leads to larger risk of structural resonances; the mistuning strength increase or coupling stiffness decrease can increase the degree of structural mode localization; the mass mistuning has greater influence on higher order mode shapes, whereas the stiffness mistuning has greater influence on the lower order mode shapes. The mistuning limits the propagation of vibration energy within ribs of antenna structure, the coupling stiffness between ribs increases to a certain value can make vibration energy spread to all the ribs uniformly