| In the existing field of damage research,damage is usually idealized into the form of through crack,but the actual situation of damage is often more complex.In order to get closer to the actual situation of damage,based on the research results of wavelet analysis and intelligent algorithm,the damage identification of structures with semi-elliptic surface cracks is studied in this paper.In this paper,through the definition of damage degree of structure with through crack and the relationship between damage degree and cross section inertia moment,the damage degree of structures with semi-elliptic surface cracks is defined and the relation between the section size,the crack depth and the damage degree is obtained.Two representative two-stage damage identification methods,namely the wave-bat algorithm and the wave-bacteria foraging optimization algorithm,were selected to identify the damage of simply supported beams with through cracks respectively.The damage location of the beam was identified by the maximum value of the wavelet system mathematical model.At the same time,the two methods are verified by numerical simulation and their advantages are analyzed.Based on wavelet analysis and intelligent algorithm for the first time the two-stage damage identification method to study the half elliptical crack in beam structure damage identification problem,through the numerical simulation successfully identified two types of damage of the beam under the condition of damage location and damage degree,this paper is verified by fitting the section size,the crack depth and the damage degree of the correctness of the expression between epsilon.By comparing the recognition results of wavelet-bat algorithm and wavelet-bacteria foraging optimization algorithm,the superiority of the two methods in damage identification of beams with semi-elliptic surface cracks is studied.The damage identification tests of beams with two different crack types are designed and completed in this paper.Firstly,the damage identification test was carried out on the structure of simply supported beam with through cracks,and the damage degree and location of the beam were identified respectively by the wavelet-bat algorithm and the wavelet-bacteria foraging optimization algorithm.Secondly,the damage identification tests of simply supported beams with two different elliptic sizes were completed,and the above two methods were used to identify the damage of beams.Test results show that the semi elliptical surface crack in structure two-stage damage identification method can be used to identify the damage location and damage degree,the section size,the crack depth and the damage degree is verified the rationality of the function relationship between epsilon,proved that based on wavelet analysis and intelligent algorithm two-stage damage identification method is of certain value to practical engineering.In addition,in this article,through contrastive analysis of the experiment and numerical simulation,show that in the practical engineering,precision and signal denoising will become the key to reduce the damage identification error,back to more accurately identify the damage degree laid the foundation experiment,comparison and analysis of the two methods are also provides reference for rational selection of damage identification methods. |
