Structural Damage Identification Based On Wavelet-Genetic Annealing Algorithm

The structure will inevitably be affected by environmental erosion,external load and material aging and other factors in the process of using.These factors will result in the damage of the structure and the decrease of the bearing capacity,which will pose a threat to the safety of the structure,and even lead to the overall destruction of the structure,which will lead to the occurrence of catastrophic accidents.Therefore,the effective damage detection method is used to detect the damage of the structure as soon as possible,and to give an accurate assessment of the damage of the structure,which has a very important theoretical significance and engineering application value.Wavelet analysis is a signal analysis method,it can well characterize the local features of the signal,and can analyze the singular point of the signal.Therefore,it can be used to accurately identify the damage location of the structure.Genetic simulated annealing algorithm is a hybrid optimization algorithm,which has good search ability and fast convergence speed,it can be used to accurately identify the damage degree of the structure.In this paper,two methods are combined to propose a structural damage identification method based on wavelet-genetic simulated annealing algorithm.In this paper,the damage identification of a simply supported beam with multiple damage is studied.Firstly,the damage location of the structure is obtained by using the finite element method and wavelet analysis theory.Then the objective function is established by using the natural frequencies and modal shapes of the structure,the damage degree of the structure is taken as the design variable.Genetic algorithm,simulated annealing algorithm and genetic simulated annealing algorithm are used to identify the damage degree of the simply supported beam.Each of the three algorithms is iterative computation,so as to realize the identification of the damage degree of the structure.Through the analysis and comparison of damage identification results of the three algorithms,it is found that the genetic simulated annealing algorithm has higher recognition accuracy when compared with the genetic algorithm,and has faster convergence rate compared with the simulated annealing algorithm.In order to further verify the feasibility and superiority of wavelet-genetic annealing algorithm for damage identification,the wavelet-genetic annealing algorithm proposed in this paper is applied to the damage identification of continuous beam.The problem of damage identification of continuous beams with 2,3 and 4 damage locations is studied.Numerical simulation results show that the method is effective,especially for the degree of small damage,it also has a good recognition effect.Therefore,this method can be used as a reference for damage detection of engineering structures.