一种轻质大柔性索网结构模态测试技术
A New Modal Testing Technique for Light-weight Large Flexible Cable-net Structure

针对轻质大柔度空间索网天线的结构特点及其动力学特性，提出了一种适合于该类索网结构的模态测试技术。设计了一套适用于索网结构激励的非接触气动激振系统，采用三维扫描激光测振系统（3D SLDV）进行非接触振动测量，并利用随机减量技术（RDT）及Ibrahim时域法（ITD）识别结构的模态参数。研究表明，运用本试验方法成功进行了索网结构振动模态测试，拓展了常规的模态试验手段，具有广阔的推广应用价值。
According to the structural features and dynamics characteristics of light-weight large flexible space cable-net antenna, a new modal testing technique is proposed in this study. A non-contact pneumatic excitation system is designed and applied to excite vibration, which is suitable for cable-net structure. The 3D scanning laser Doppler vibrometer (3D SLDV) is used to conduct non-contact vibration measurement. The structural modal parameters of cable-net antenna are identified based on the time domain modal analysis method of random decrement technique (RDT) combined with Ibrahim time domain method (ITD). As an extension to conventional modal test methods, the current technique has successfully obtained the vibration modes of a light-weight large flexible cable-net structure, showing a promising prospect of applications