Study On Frame Structure Damage Identification Based On Wavelet-Bat Algorithm

With the advancement of the social sciences,the civil engineering field is also undergoing tremendous changes,and various large and complex structures have emerged.Due to the com-plexity of the external environment and various human factors in the use process,the structure will inevitably be damaged during the service.Based on the research of structural damage identification methods at home and abroad,this paper combines wavelet analysis and bat algorithm to study structural damage identifica-tion methods.As a new type of signal analysis tool,wavelet analysis has good localization and multi-resolution characteristics.Bat algorithm is a meta-heuristic algorithm with natural evolu-tionary ideas,which can be independent of the strict mathematical properties of the optimiza-tion problem itself.The algorithm is simple,the parameter setting is small,and it is easy to implement.In this paper,two methods are combined to propose a two-stage structural damage identification method.Firstly,establishing the finite element model of the structure,the angular modal data con-taining the damage information is obtained by modal analysis,the curvature modal data of the structure are derived from the angular modal data,the wavelet coefficient graph is obtained by wavelet transform of the curvature modal data of the structure,and the structure damage posi-tion is determined by observing the modulus maximum point in the wavelet coefficient graph.Secondly,the objective function is constructed by using the natural frequency and vibra-tion pattern of the structure before and after the damage,and then the bat algorithm is used to optimize the objective function to obtain the optimal solution,and the damage degree of the structure can be obtained by the optimal solution.In order to verify the feasibility of the method proposed in this paper,a numerical simula-tion analysis of a layer of one-span frame structure containing damage is carried out,and the results show that the method can effectively identify the damage position and damage degree of the structure,and verify the effectiveness of the method.In order to further verify that the method can be applied to the identification of complex structural damages,a two-layer and two-span frame structure with damage is established.The damage location of the structure is analyzed by wavelet analysis.Then the bat algorithm is used to identify the damage degree.The results show that the method The location of the structural damage and the degree of damage can be accurately identified.By analyzing the results of the two algorithms,it is found that the bat algorithm has more obvious advantages in terms of convergence speed and accuracy.Therefore,the method proposed in this paper has certain ref-erence value for structural damage identification.