Intelligent damage identification method for jacket type ocean platform

Abstract

The invention discloses an intelligent damage identification method for a jacket type ocean platform. According to the intelligent damage identification method, modal parameters are extracted by adopting a CP algorithm. The adaptability of the algorithm for processing high-damping and high-order complex modes is higher than that of a traditional blind source separation algorithm, such as an ICA algorithm; the CP algorithm adopted by the invention has a direct and effective implementation mode, parameters do not need to be adjusted in the application process, the length of a system vibration response signal does not affect the result accuracy, and complete blind identification can be carried out on modal parameters of various structures; according to the PSO-SVM model provided by the invention, under a small sample condition, the accuracy of a damage identification result is better than that of a traditional intelligent algorithm such as an SVM and a BP neural network, and a model hyper-parameter does not need to be manually adjusted so that a use threshold is reduced; the method provided by the invention has relatively high noise robustness. Experiments show that the method has high identification accuracy under the condition that the noise-to-signal ratio is less than 17.8%.

Description

technical field [0001] The invention relates to the technical field of ocean engineering and structural health monitoring, and more specifically, to an intelligent identification method for jacket type offshore platform damage. Background technique [0002] Damage identification for large and complex structures has always been a research focus and difficulty in the field of structural health monitoring. Damage location and damage quantification are the main problems to be solved in structural damage detection. Experimental modal analysis (EMA) based on the relationship between input and output of traditional systems is usually applicable under the conditions of controllable excitation or known excitation, and it is difficult to apply to large structures such as offshore structures, bridges, buildings, etc. Therefore, the problem of output-only mode identification of complex structures is usually solved using operational mode analysis (OMA) and signal processing techniques. ...

AI Technical Summary

Problems solved by technology

However, the ICA algorithm is only suitable for undamped and lightly damped structures; the SOBI method is not accurate for the identification of non-diagonalizable damping

In addition, the basic form of ICA ignores the time structure and only uses non-Gaussian criteria; and, the sample duration will affect the recognition accuracy of ICA

Therefore, the application of ICA to identify the vibration signals of large and complex structures will cause problems such as excessive errors or mode aliasing.

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