The Research Of Structural Damage Identification By ACO Algorithm And Wavelet Theory

building structures will be affected by various anthropogenic factors,load factors and environmental factors,these factors may lead to some parts of the building structure has a certain degree of damage,a threat to the safety of building structures,and even cause catastrophic accidents in engineering.Therefore,it is of great significance to study the method of structural damage identification.Wavelet analysis was a time-frequency analysis method and has the function of multiresolution analysis.The wavelet analysis window has good adaptability in both time and frequency regions,so wavelet can show the local characteristics of the signal and can be more effectively identified signal singularity,therefore wavelet analysis can identify the damage location of the structure effectively.Ant colony algorithm is a new bionic intelligence algorithm,Ant colony algorithm is not dependent on the problem of rigorous mathematical logic in the process of solving,and it has stron adaptability,robustness,compatibility and global optimization search ability.Based on the advantages of wavelet analysis and ant colony algorithm,this paper presents a two-stage structure damage identification method,namely wavelet-ant colony algorithm.Firstly,the damage location of the structure is identified by wavelet analysis,and then the damage degree of the structure is identified by the ant colony algorithm.In this paper,the damaged structure is taken as the object of study,and the principle of wavelet-ant colony algorithm which can identify the damage location and damage degree of the structure is given.Firstly,the modal parameters of the structure are obtained by the finite element method,and the damage location of the structure is determined by wavelet analysis.Then,the objective function of the algorithm is constructed based on the natural frequency and the curvature modal of the structure,then the corresponding ant colony algorithm program is compiled.he ant colony algorithm is carried out to search in the corresponding search domain,so as to identification of damage degree.In this paper,the damage identification problem of three-span continuous beam is studied by using wavelet-ant colony algorithm.Firstly,the finite element model of three-span continuous beam is established.The finite element analysis of continuous beam with single damage and three damage is carried out.The damage position of continuous beam is determined by wavelet coefficient modulus maxima.And then the compiled ant colony algorithm was used to identify the damage degree of three-span continuous beam including single and three damage.The validity of the method is verified.In this paper,wavelet-ant colony algorithm is used to study the damage identification problem of one-layer and one-span structures(including two damage and three damage)and two-layer and two-span structures(including three damage and four damage).wavelet-ant colony algorithm was used to effectively identify the damage location and damage degree of these frames,which indicates that the method can be effectively used in complex structures and multi-damage structures.Therefore,this method has reference value for damage detection of engineering structure.