Updating the finite element model of bridge structures by an improved Taguchi updating method

In the procedure of model updating, the objective function is usually set as the weighted sum of the difference between analytical and experimental dynamic characteristics of structures. But it is difficult to select the weighting factors since the relative importance of each parameter to the updated results is not obvious but specific for different problem. To overcome this problem, multi-objective genetic algorithm (GA) is introduced into model updating since there is no need for selecting weighting values. However, the present updating methods based on GA is difficult to be applied to update the finite element model of civil structures by reason of low efficiency. To develop an efficient multi-objective updating method, an improved Taguchi updating method is proposed, which has the ability to solve the multi-objective optimization problem by introducing the classification of searching population and the new objective function. And then a parameterizing scheme for structural boundary condition is proposed, and the proposed updating method is employed to update boundary conditions of a truss bridge structure.