Study on vibration characteristics of the dike crossing pipeline based on EWT and CWT.

The dike crossing pipeline is an important part of urban water transmission and supply projects. Identifying effective vibration analysis methods to determine the primary vibration sources and coupling vibration characteristics of pipelines is crucial for targeted vibration reduction and reinforcement of vulnerable pipeline sections. Therefore, this paper proposes a coupled vibration characteristics analysis method for the dike crossing pipeline based on EWT and CWT, taking the 6# dike crossing pipeline of Yang'er water plant in Foshan city, Guangdong province as the research object, firstly, the main vibration sources of the dike crossing pipeline are analyzed with the help of the prototype observation data using the mutual correlation power spectral, and the characteristics of the main vibration sources of the pipe are extracted using the empirical wavelet transform (EWT); then, focusing on the main vibration source, wavelet transform is used to analyze the source characteristics of the dike crossing pipeline; finally, the pipeline coupled vibration characteristics are analyzed using the cross wavelet transform (CWT). The research results show that: 1) The vibration of the 6# dike crossing pipeline of Yang'er water plant is mainly caused by the multiple rotational frequency such as 29.5 Hz, 36.5 Hz and the leaf frequency 59.0 Hz; 2) The EWT method can effectively remove the interference signal and extract the characteristic frequencies 29.5 Hz, 36.5 Hz and 59.0 Hz; 3) Analyzing the coupled vibration characteristics of the dike crossing pipeline based on the CWT, the peak energy of the coupled vibration of the 6# pipeline is generally concentrated at the frequency of 29.5 Hz, and the source of the coupled vibration is the multiple rotational frequency of the 6# pipeline unit. The results of this study can offer new insights into the identification of vibration characteristics of the dike crossing pipeline, and can provide technical support for the analysis of vibration characteristics and reduction needs of similar projects.