Structural damage identification method based on displacement response covariance parameter and Bayesian fusion

Abstract

The invention discloses a structural damage identification method based on displacement response covariance parameters and Bayesian fusion, comprising the following steps: arranging an acceleration sensor on the structure to record structural response information, and performing secondary integration on the acceleration response to obtain the displacement response , or directly test the displacement response; calculate the "equivalent strain response" and unit impulse response of the unit before and after the structural damage, and the covariance CoD of the unit displacement response; calculate the change distribution vector of the covariance CoD of the unit displacement response before and after the structural damage , and transform it into a damage probability vector; apply the Bayesian formula to calculate the posterior damage probability vector; finally, through certain criteria, select the appropriate posterior damage probability as the final damage identification result of the unit. The method of the invention can effectively determine the occurrence of damage and identify the damage location, does not need a structural analysis model, is simple to calculate, has good noise robustness, and has good engineering applicability.

Description

technical field [0001] The invention belongs to the field of structural health monitoring, and relates to a structural damage identification technology, in particular to a structural damage identification method based on displacement response covariance parameters and Bayesian fusion. Background technique [0002] There are more and more civil engineering structures in the world. These structures are often large and complex. The performance of the structure will inevitably decline or even be damaged, eventually leading to partial or even overall collapse of the structure. When an accident occurs, it will not only cause huge economic losses, but also endanger people's lives. Therefore, health monitoring of civil engineering structures is very necessary. [0003] In recent decades, structural damage identification methods based on vibration parameters have also been proposed. Vibration parameters include frequency, mode shape, frequency response function, modal strain energy,...

AI Technical Summary

Problems solved by technology

However, the following problems hinder the application of these damage identification methods in actual engineering structures. First, when performing modal identification, problems such as subjectivity error, power spectrum leakage, dense mode loss, and truncation error will inevitably occur; Second, in the time-domain damage identification method based on vibration parameters, there is a problem of system order determination and mode loss; third, it cannot contain more order modal information as much as possible, and the response signal is lost. The high-order modes related to damage make the extracted indicators not sensitive enough to damage; fourth, some methods require manual participation in the calculation, resulting in the randomness of manual intervention, which is not suitable for automatic online analysis and health monitoring of massive continuous monitoring data; fifth , because there are too many uncertain factors in the actual engineering structure, it is difficult to establish an accurate matching structural analysis model, which makes it difficult to apply the damage identification method relying on the structural analysis model to the actual engineering structure

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