Research on damage identification of girder bridge based on model correction and gray system theory
In order to carry out the damage identification analysis of existing girder bridge structure,it is necessary to rely on finite element software to establish an ideal bridge numerical model.However,the finite element model of the girder bridge established based on the design drawings has not yet taken into account the uncertainty of the modeling process,and the calculation of the finite element model has a large deviation from the actual measurement of the existing bridge.Using the model modification method based on BP neural net-work optimized by genetic algorithm,numerical analysis is carried out on the modified finite element model which is closer to the actual girder bridge structure,and gray system correlation analysis and damage identifi-cation are carried out through the deflection influence line.The results show that the proposed model modifica-tion method based on genetic algorithm optimized BP neural network makes the finite element model close to the actual structural model,and combined with the field modal test,the resultant frequency error decreases from the uncorrected 30.5%to the corrected 9.8%.The damage identification results show that the gray sys-tem theory correlation coefficient is linearly related to the damage degree,and the smaller the gray system cor-relation coefficient is,the greater the damage degree is.
bridge engineeringmodel correctiondamage identificationgenetic algorithmgray sys-tem theory