Damage Diagnosis Using Experimental Ritz Vectors

This paper describes an experimental study on the use of Ritz vectors for damage detection of a grid-type bridge model. A new procedure to extract Ritz vectors from experimental modal analysis is proposed and demonstrated using the test structure. The extracted Ritz vectors are then used for the damage detection of the test structure using a Bayesian probabilistic approach. Using appropriate load patterns, Ritz vectors can be made more sensitive to damage than modal vectors. The results indicate that the use of load-dependent Ritz vectors produce better damage diagnoses than the modal vectors. The Bayesian probabilistic approach is shown to give better diagnostic results than commonly used deterministic methods.