QUALITATIVE AND QUANTITATIVE IDENTIFICATION OF MULTIPLE DAMAGES BASED ON INCOMPLETE FREQUENCY RESPONSE FUNCTIONS

Conventional methods using frequency response functions are effective to detect single damage, but are difficult to identify multiple damage locations and extents. In order to solve this problem, a two-stage method using incomplete frequency response functions is presented. The damage detection strategy is to localize the damage locations by using damage index of different nodes or degree-of-freedoms, which can be obtained from measured incomplete frequency response functions. A damage quantification formula is then deduced from the reduced degree-of-freedom system to calculate damage extents. The simulation results demonstrate the excellent performance of the proposed two-stage method based on degree-of-freedoms damage index to detect multiple damages as compared with other methods.