Abstract:

Aviation pipeline is one of the key components of aircraft;aimed at the influences of damping ratio in dynamics computation,based on MIMO modal test,a pipeline,made of aviation aluminum alloy,its first eight order modal frequencies and damping ratios were obtained.In addition,the pipeline was excited by instantaneous loads and the response data in some regions were gotten in time domain.The mode frequencies were calculated by taking into account the added mass caused by acceleration sensors.Respectively,based on constant damping ratio and modal damping ratio of testing mode,the instantaneous dynamic responses of the pipeline were analyzed and compared with test values.The results show that both of dynamics response amplitudes and the response times in calculation based on modal damping ratio are
closer to test values of the aviation pipeline,it is better than that of the calculated values based on constant damping ratio.The structure with high security requirements,such as aviation pipeline,its response should be calculated based on the modal damping ratio as far as possible. 

Key words: aviation pipeline, modal test, damping ratio, dynamics response

摘要：

航空管道是影响飞行安全的关键件之一,针对其动力学特性分析中阻尼比的影响问题,对某航空铝合金管道采用MIMO模态测试,得到其前八阶模态频率和阻尼比;对该管道施加瞬态激励,得到不同点处的时域响应数据;考虑了传感器的附加质量,计算了模态频率,分别基于恒定阻尼比和实验得到的模态阻尼比模型,分析了管道瞬态动力学响应特性,并与实测响应数据进行对比分析。结果表明：采用模态阻尼比计算得到的管道动力学响应不论是响应时间还是响应大小都更接近于实测值,对于航空管道这种安全性要求很高的结构,应尽可能采用模态阻尼比进行计算分析。

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关键词: 航空管道, 模态测试, 阻尼比, 动力学响应