An evolutionary multiobjective framework for structural damage localization and quantification

Damage identification techniques based on changes in modal flexibility have been widely used. However, this parameter, although sensitive for detecting the existence of damage, is not very suitable for locating it. In this paper a method to detect, locate and quantify structural damage is presented. In order to do this, an objective function dependent on modal flexibility is combined with another function able to predict damage location. The problem is formulated as a multiobjective optimization problem of finding the Pareto optimal damage distribution that simultaneously minimizes the two objective functions. Then, a genetic algorithm suitable for solving general multiobjective optimization problems is applied. The effectiveness of the proposed algorithm is illustrated for simulated beams and by using directly experimental data from the vibration tests of a beam. It has been verified that the proposed procedure is very promising for locating and quantifying damaged elements and considerably improves predictions based only on modal flexibility parameters.