Based On The Grey System Theory Of Bridge Structure Damage Identification Research

For large or damaged bridge structure,because of the limitation of conditions,the observed data is often limited.The grey system theory by studying inadequate,incomplete data information,to analyze the characteristics,form and change trend of the system.Aiming at the problem of damage diagnosis of bridge structure,this paper linked the knowledge of gray correlation degree with curvature mode,and verified the method by using the simply supported beam model established by finite element software and the bridge model made by plexiglass,and achieved a good recognition effect.The main work of this thesis includes:1.This paper summarized the methods of structural damage diagnosis,and analyzed the method of structural damage diagnosis based on static detection information and dynamic detection information,then analyzed the principle and advantages and disadvantages of the two methods.And the main problems in the methods of structural damage diagnosis are summarized.2.A detailed study and introduction of the gray system prediction model and several major gray correlation degree are made.According to the sensitivity of curvature mode to structural damage,the relationship between gray correlation degree and curvature mode is analyzed,and the gray curvature degree is used to determine the damage of the structure,and good results are obtained.3.Through the finite element simulation and the plexiglass simply supported beam test,the damage diagnosis method based on the gray curvature correlation degree is verified,and the different damage conditions are simulated with different crack depth,effectively discriminated the structural damage location.4.The structural damage diagnosis method based on the gray system theory is compared with the structural damage diagnosis method based on the statistical model and the wavelet packet energy method.The advantages and disadvantages of ea ch method are analyzed by the same experimental overview,highlighting the practicality of gray system theory in structural damage diagnosis.