空间薄壁CFRP豆荚杆模态试验及分析

摘要

空间薄壁CFRP豆荚杆工作时处于悬臂状态,为掌握其结构动态响应,对10 m长的超长薄壳豆荚杆在下端刚接约束下进行模态试验,得到了其模态和频率.利用有限元软件ADINA对试验模型在不考虑和考虑空气的情况下进行数值模拟分析,得到其在下端刚接约束下的模态和频率.数值模拟与试验结果对比分析表明:对于该试验研究对象,沿弱轴方向的基频,不考虑和考虑空气的计算结果和试验的误差分别为36.4％和4.7％,因此在地面试验和数值分析的过程中需要考虑空气与结构耦合的影响.进一步对豆荚杆的杆长进行参数化分析,得到了3～10m豆荚杆的基频在不考虑空气和考虑空气影响下的偏差.对悬臂薄壁CFRP豆荚杆的设计、应用具有重要参考价值.%When space thin-walled carbon fiber reinforced plastic (FRP) lenticular booms are working,they are in a cantilever state.In order to know their structural dynamic responses,a 10 m-long thin-walled CFRP lenticular boom with its bottom end fixed was tested to obtain its modal frequencies and modal shapes.The FE model of the boom was built with the FE software ADINA,it was used to perform numerical simulation without air and with air surrounding,respectively to gain its modal frequencies and modal shapes.The numerical simulation results were compared with those of modal tests.It was shown that for the fundamental frequency of the tested boom,the error between the calculation value and the tested one is 38.40％ without air and 4.7％ with air,so considering the influence of air is necessary;the effects of the boom length on its fundamental frequency is also analyzed;when the boom length is 3-10 m,the deviations between its fundamental frequency value without air and that with air are obtained.The results provided a reference for optimization design of space thin-walled CFRP lenticular booms.