航天器微振动工装动力学特性仿真分析与试验验证

Simulation and experimental verification of dynamic characteristics of spacecraft micro-vibration test fixture

微振动试验中为了模拟航天器的在轨自由边界,需要建立具备大承载低刚度的试验工装。文章提出一种简化的航天器与微振动工装组合体模型,引入考虑初始变形的模态分析理论对组合体模态频率特性进行仿真分析,并将某型号卫星微振动试验工装设计指标与试验测试指标进行对比。结果表明:用简化后的组合体模型计算得到的准刚体模态频率与实测值相近,简化模型提供的第六阶频率计算误差仅为0.3%,从而验证了分析模型与校核方法的有效性。

To simulate a spacecraft on orbit with a free boundary, a micro-vibration test fixture with a large bearing capacity and a low stiffness should be established for the micro-vibration test. A simplified combination model for analyzing the micro-vibration fixture is presented in this paper. The modal analysis with consideration of the initial deformation is made to obtain the frequency characteristics of the assembly. The testing result of a typical satellite micro-vibration test fixture is used for comparison. The comparison between the analysis model and the testing results shows a 0.3% error for the sixth order frequency evaluation.