Modal Frequency Identification of Quayside Container Crane Based on Empirical Mode Decomposition and Power Spectrum

Abstract

Hilbert-Huang Transform (HHT) causes modal aliasing and false modes in identifying modal frequencies of structures, thus a power spectrum modal frequency identification method based on Empirical Mode Decomposition (EMD) is proposed. The paper chooses quayside container crane (QCC) as the object of research. Firstly, the finite element model of QCC is established to identify the modal frequencies by modal analysis. Secondly, EMD is applied to the monitoring signals of QCC. According to the principle of correlation, the effective Intrinsic Mode Function (IMF) components are screened to identify the modal frequencies by power spectrum. The experimental results show that the method of frequency identification is close to the results of finite element frequency identification, and can effectively eliminate the false modes, improving the efficiency of frequency identification. The results of identification are more intuitive.