Damage Identification Of Bridges Based On Structural Dynamic Characteristics

In recent years,China's economy has developed rapidly,and the transportation industry has also developed rapidly.At the same time,it has occupied an increasingly important position in our work and life.At the same time,many bridges have been built,and bridges inevitably play an important role.The safe use is related to people's life safety and property safety.The health status of the bridge structure has great influence on the safety of its operation,so it is particularly important for the health damage identification of the bridge structure.Its research analysis has a high theoretical significance and practical value.This paper describes the characteristics and application background of the neural network damage identification method.In addition,a single damage model with different degrees for simple supported beam bridges and different degrees of damage models for continuous beam bridges are established through Midas finite element software.Analyze,extract modal parameters of the structure and process it for damage identification.The analysis results show that the frequency parameters such as frequency change,frequency change ratio,frequency change square rate,and regularized frequency change rate can well determine the damage location for single-supported beam bridge damage.Curvature parameters such as curvature modality value,curvature modality difference,and curvature modality change rate not only can be used for damage identification of simply supported beam bridges,but also can be used to identify the damage of continuous beam bridges in multiple locations..In the finite element analysis,the simple-supported beam bridge model adopts a rectangular section,and a finite element model is established by Midas.Then the modal analysis of the simply supported beam model is performed.After the modal analysis,the first five frequencies and the formation are extracted.A single damage analysis was performed for different degrees of damage at different damage locations,and damage identification was performed based on frequency parameter damage identification.Then,the first five modal parameters under non-destructive and damage conditions are extracted through curvature modal parameters for analysis.In addition,the damage location of three-span continuous box girder bridges was determined by using the curvature modal parameters.