Study on damage identification for bridge structure based on improved genetic algorithm

A damage identification method based on improved genetic algorithm (IGA) is presented that accurately identifies both the location and severity of damage in a simulated 3-span continuous beam bridge. Damage identification based on finite element model updating is often used and damage is identified by minimizing the error between measured and analytical results. But whether model updating can be carried out successfully mainly depend on accuracy of model, quality of vibration testing, definition of optimization problem and calculation performance of optimization algorithm. In the paper, the construction technique of objective function based on modal parameters is introduced firstly, an improved genetic algorithm (IGA) is presented secondly. In the end, through the simulation of a continuous beam bridge damage identification is studied comparatively. From the results it can be seen that the damage identification method developed using IGA provides greater accuracy in identifying the location and severity of damage.