The Study, Structural Damage Detection Method Based On The Acceleration Frequency Response Function

The structural damage detection technology is the foundation of structural health monitoring (SHM). People have been trying to look for the global damage diagnosis and evaluate method that can be applicable to civil engineering structure in recent years. So far, the research of the structural damage detection technique based on vibration that applied to the civil engineering structures realm has already made very obvious progress. But because the noise is existent in all engineering problem, the indetermination of the environment condition, model error margin, uncompleted measured data, the method not perfect and the insensitivity of local damage etc, most of the methods could hardly be applied in practice. Therefore, it has very important realistic meaning to research a structural damage detection technique which can be applied to actual structure and provide accurate efficiently results.In this dissertation, first, structural health monitoring (SHM) and structural damage detection are elaborated in brief, and then carried out detailed analysis of all the various damage detection methods of existence, based on the summary of advantages and disadvantages of each method, this dissertation puts forward a method to localize and quantify the structural damage using acceleration frequency response functions (FRF). This method makes use of experimental acceleration FRF and the one computed from finite element model (FEM) respectively to update the stiffness matrix, mass matrix, damping coefficient of FEM. The acceleration FRF of the FEM will be consistent with the experimental measured one after updating. The difference between stiffness matrixes before and after updating indicates the position and the extent of structural damage. The addressed method has explicit physical meaning, and doesn't need to carry out modal analysis. The results of the numerical examples verify the usefulness and the accuracy of the method.The research results show that the addressed method can get the measured data easily with good accuracy, and has a strong anti-noise ability. The algorithm is simple and clear, avoiding modal analysis, and can be applied to actual structure. To update the FEM constantly, an actual structure's state variety curve can be created,...