空间遥感器支撑桁架的模态计算与试验

为保证空间遥感器成功发射,采用有限元法计算了主要承受动力学载荷支撑桁架的模态特性,用锤击法对支撑桁架实物进行了模态测试。对计算结果与试验结果的模态频率进行了对比,用视觉比较、模态置信准则等方法进行了模态振型相关性分析。结果表明,桁架结构的一阶频率为154 Hz,满足了一阶频率＞140 Hz的设计要求;桁架结构的有限元模型平均频率计算误差＜10%,局部存在与试验结果相关性＜0.5的振型,需要进一步的修正,才能满足后续工程的应用要求。

Modal calculation and test of truss in space remote sensor

In order to launch the space remote sensor sucessfully, the modal characteristic of a truss for enduring the dynamic load was calculated by Finite Element Method(FEM), and the modal test was done by the hammer beat method. The calculated and tested frequency result was compared, and the visual comparing method and the Modal Assurance Criterion( MAC ) were employed in the relativity analysis of the modal shape. Experimental result shows that the first-order order frequency of the truss is 154 Hz, which satisfies the design requirement above 140 Hz,and the calculated error of the FEM is less than 10%. There are some shape relativity less than 0.5 in partly,so the FEM model needs to be modified for the following engineering use.