基于模态理论的振动结构声辐射信号特征提取方法及其应用

论述了结构振动与声辐射之间的传递特性,以堆垛机结构为对象进行了试验研究。通过模态参数测试和声辐射信号分析验证了理论分析的正确性。提出了一种基于模态频率的声信号频域特征信息提取方法,并将该方法用于堆垛机结构的冲击载荷分类识别研究。结果表明,声谱峰值频率与结构模态频率具有相当好的一致性,声谱幅值分布反映冲击载荷的特性;采用所提出的方法提取的声信号特征信噪比高,用于振动结构冲击载荷分类识别是合理的和有效的。由于设备发生故障必然导致载荷的变化而使所辐射的声信号发生变化,加之声信号获取成本低且有近场非接触测量的优点,所以提出的声信号特征提取方法在机械设备运行状态监测和故障诊断方面具有重要的应用价值。

METHOD FOR SOUND SIGNAL CHARACTERISTIC EXTRCTION BASED ON MODAL ANALYSIS AND ITS APPLICATION

The fundamental relation between structural vibration and acoustic radiation is discussed based on the theory of structure vibration modal analysis. An experiment is used for verification. The result of examination and analysis shows that frequencies of the peak value in sound signal power spectra are consistent with the structure modal frequencies. A new approach is presented for feature extraction from sound signals generated by the structure sound radiation in frequency domain using modal frequency. The approach was used to identify the loading pattern classification on the specific machine structure. The research result clearly expresses that the approach is reliable and effective for loading pattern classification. The approach is very useful for application on machinery operating state inspecting and fault diagnosis, because that the obtaining of the sound signal is easy and the cost is low as well as the method of measurement does not touching.