摘要
为了对螺旋桨的模态参数进行无接触式测量,首先基于声学边界元方法,建立了螺旋桨在冲击载荷作用下辐射声信号与模态参数之间的数学模型,该模型相比于已公开文献采用的模型,从理论上揭示了采样声信号不必须取自于结构近场。在此基础上,借助希尔伯特-黄变换(Hilbert-Huang transform, HHT)方法处理非平稳、非线性信号,对采样声信号进行处理来识别结构模态参数。以一螺旋桨缩尺模型为研究对象,分别采用数值模拟和试验手段对该方法的实用性和有效性进行了验证,并评估了环境噪声的影响程度。结果显示该方法能准确识别模态频率和阻尼比,且具有自适应频率分辨率,为工程上精细结构的模态参数识别提供一种新途径。
Here, to conduct non-contact measurements of propeller modal parameters, firstly, based on acoustic boundary element method, a mathematical model for relation between propeller radiating sound signals and its modal parameters under impact load was established. Compared with the model adopted in published literature, this model theoretically revealed that the sampled sound signals don’t have to be taken from near field of structure. Then, with the help of advantages of Hilbert-Huang transform(HHT) in processing non-stationary and nonlinear signals, the sampled sound signals were processed to identify structural modal parameters. Taking a scaled propeller model as the study object, the practicability and effectiveness of this method were verified with numerical simulation and test means, respectively, and effects of background noise were evaluated. The results showed that the proposed method can correctly identify modal frequencies and modal damping ratios, and have self-adaptive frequency resolution;it can provide a new way for modal parameters identification of fine structures in engineering.
作者
刘正浩
丁举
毛献群
LIU Zhenghao;DING Ju;MAO Xianqun(Marine Design and Research Institute of China,Shanghai 200011,China;Science and Technology on Waterjet Propulsion Laboratory,Shanghai 200011,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2023年第3期57-63,73,共8页
Journal of Vibration and Shock
基金
上海市领军人才基金。
关键词
螺旋桨
声信号
模态参数识别
希尔伯特-黄变换
propeller
sound signal
modal parameters identification
Hilbert-Huang transform(HHT)
