Bridge damage identification method based on non-iterative finite element model correction

Abstract

The invention discloses a bridge damage identification method based on non-iterative finite element model correction, and the method comprises the steps: employing the acceleration response of a bridge under the action of pulse excitation or environment excitation, and recognizing the inherent frequency, damping ratio and vibration mode of the bridge from the acceleration response through a random subspace algorithm; the identified modal parameters are utilized to reconstruct characteristic values and characteristic vectors of a state space matrix according to a preferred direction and sequence, and the characteristic values and the characteristic vectors serve as targets of modal parameter assignment in the non-iterative finite element model correction process; therefore, the state space matrix of the initial bridge finite element model is uniquely corrected, the updated bridge rigidity and damping matrix is calculated through the state space matrix, and then the damage position and degree of the bridge are identified by using the change of the units in the updated bridge rigidity matrix. The method can effectively solve the problem that most existing bridge damage recognition based on iterative finite element model correction is large in calculation workload, so that the damage recognition efficiency can be improved, and the calculation cost is reduced.

Description

technical field [0001] The invention relates to the field of bridge safety monitoring and detection, in particular to a bridge damage identification method based on non-iterative finite element model correction, and the update result can be used for damage identification and safety assessment of bridge structures. Background technique [0002] With the development of the finite element method, the finite element model can be used to calculate the dynamic response of the bridge under various loads and various boundary conditions. The analysis speed is fast, the structural design period is short, and the efficiency and cost are high compared with the structural dynamic test. It can be widely used in bridge structural health monitoring. Therefore, a reliable and accurate finite element model is the basis for bridge structural damage identification, health diagnosis, and bridge working condition evaluation and prediction, that is, the premise of damage identification is to modif...

AI Technical Summary

Problems solved by technology

However, the optimization techniques used in most finite element model correction methods are iterative, and it takes a lot of time and cost to calculate the updated stiffness and damping matrix of the bridge, and iterative model correction based on frequency and mode shape needs to determine the frequency and mode shape in advance Weights

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