Transmission tower modal parameter identification method based on improved subspace algorithm

Abstract

The invention discloses a transmission tower modal parameter identification method based on an improved subspace algorithm and used for completing the modal parameter identification of a large span transmission tower structure through individually utilizing response data under the excitation of a field environment. According to the identification process, multi-group packet response data are integrated into synchronous pulse response data based on a random subspace identification principle; the integrated data avoid fitting errors caused by the packet identification, so the synchronous integrated identification of the data is realized; and a stable graph is constructed by utilizing modal parameter identification results under different system orders, so a modal parameter identification order determination problem under the environment excitation is solved, modal omission and repetition phenomena of traditional methods of a peak value method and the like are avoided, the obtained identification result is accurate and stable, and bases are established for subsequent structure damage detection and life estimation.

Description

technical field [0001] The invention relates to a large-scale structure test modal analysis technology, in particular to a transmission tower modal parameter identification method. Background technique [0002] Large-scale structural test modal analysis technology is one of the effective methods for structural health and safety assessment developed in the new century. The on-site measurement of the dynamic characteristics and dynamic response of the transmission line tower prototype has only been carried out in recent years. Because the testers work at high altitude near the high-voltage electric field of the transmission tower prototype, the measurement working conditions are very difficult; the vibration signal is weak in the breeze, and the signal-to-noise ratio of the measurement sensor and instrument is high; the whole tower modal test In order to obtain a more reliable vibration shape, More measuring points are required, and a large number of channels are required for...

AI Technical Summary

Problems solved by technology

[0015] The purpose of the present invention is to solve the limitations of the existing frequency-domain identification algorithm based on environmental excitation and the difficulty that all test points cannot be measured synchronously for large structures, improve the existing random subspace modal parameter identification algorithm, and improve the modal The identification accuracy of parameters improves the defects of artificial modal order determination

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