Method for predicting structural deformation by analyzing power signals in narrowband range

Abstract

The invention discloses a method for predicting structural deformation by analyzing power signals in a narrowband range, which comprises the following steps that: the structure reaction power signals are observed by an impact vibration test of a civil structure, and a frequency domain transfer function of the structure is obtained by Fourier transform and spectral analysis; the whole frequency space of the frequency domain transfer function is divided into two to five continuous narrow subspaces; the modal parameter of each subspace is identified; and according to the modal superposition theory, the identification results of the subspaces are superposed, and the structural modal parameters are calculated and further the overall flexibility matrix is calculated. In the method, firstly, the overall frequency domain is divided into a plurality of narrowband regions, and the experimental data are analyzed in each narrowband region, and finally the analysis results of each narrowband region are integrated to identify the flexibility matrix of the structure, and thus the structural deformation of the structure under any static load is predicted. The method has the characteristics of short calculation time and high accuracy of predicted results, and is suitable for the health diagnosis and the security assessment for various engineering structures, especially the civil structure.

Description

technical field [0001] The invention relates to a method for analyzing structural vibration test data in a narrow frequency range, which can realize deformation prediction and health diagnosis of civil engineering structures. Background technique [0002] Vibration testing is the main method for health diagnosis and safety assessment of existing civil structures. By arranging accelerometers and other types of sensors to civil structures, conducting vibration tests and then analyzing the test data, the main parameters of civil structures can be identified so that structural health diagnosis can be performed. Research and engineering practice have shown that due to sensor sensitivity and experimental environment, the measured vibration data contains various noises. How to accurately analyze structural characteristics from test signals with poor signal-to-noise ratio is an important content in structural health diagnosis. . In addition, most of the existing health diagnosis m...

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Problems solved by technology

In addition, most existing health diagnosis methods based on acceleration signals only output the modal parameters (frequency, damping, formation) of the structure, but cannot directly predict the deformation of the structure

These reasons limit the application of structural health diagnosis technology in civil engineering. Therefore, to develop a stable and reliable dynamic signal analysis method to identify structural detailed structural characteristics (such as flexibility matrix) from the dynamic signal obtained from vibration tests can predict The deformation of the structure will promote the application of health diagnosis technology in engineering practice

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