双台振动试验相干系数的选择  

The selection of coherence coefficient of two-stage vibration test

作　　者：杨蔚原[1] 张青虎 杨正玺 YANG Weiyuan;ZHANG Qinghu;YANG Zhengxi(Beijing Institute of Mechanical and Electrical Engineering;National Key Laboratory of Complex Multibody Dynamics,Beijing 100074,China)

机构地区：[1]北京机电工程研究所 [2]复杂多体动力学全国重点实验室,北京100074

出　　处：《航天器环境工程》2024年第6期699-706,共8页Spacecraft Environment Engineering

摘　　要：针对目前飞行器双台振动试验中没有互谱条件而导致难以选择和设置与互谱相关的相干系数的问题,进行了理论分析和试验研究:分析飞行器在飞行中和地面振动试验中的激励源的相关性,明确了试验中相干系数的确定原则;通过统计分析得出了试验中相干系数超差在频率分布上的规律以及异常超差的原因;同时通过细长体飞行器双台振动试验验证了不同相干系数设置在测点响应量级、均衡速度和驱动量级方面的试验效果差别。根据分析与试验结果提出了分频段选择不同相干系数以及有限放大容差的设置方法。试验证实了该设置方法的可行性。研究结果对于多台振动试验互谱设置有指导意义。Currently,the absence of cross-spectrum conditions in the two-stage vibration testing of aircraft complicates the selection and setting of coherence coefficients related to the cross-spectrum.This paper presented a theoretical analysis and experimental investigation to address this issue.The study analyzed the correlation between excitation sources during flight and ground vibration tests to elucidate the principles for determining coherence coefficients in testing.Through statistical analysis,the patterns of coherence coefficient deviations across frequency distributions and the reasons behind abnormal deviations in tests were identified.The impact of different coherence coefficients on response magnitude,equilibrum speed,and driving magnitude at measurement points was verified using a two-stage vibration test on a slender body spacecraft.Based on the analysis and test results,a method for selecting coherence coefficients for various frequency bands with moderate amplification tolerance was proposed.The experiment demonstrates the feasibility of the proposed method,and the findings can be applied to establish cross-spectra in multi-stage vibration tests.

关 键 词：双台振动 相干系数 互谱 振动控制 多输入多输出 

分 类 号：TB123[理学—工程力学] V416.2[理学—力学]