A MULTIPLE-DAMAGE LOCATION ASSURANCE CRITERION BASED ON NATURAL FREQUENCY CHANGES

A new method for locating multiple damage sites in elastic structures is introduced. It uses only the natural frequencies for diagnosis and obviates the need to have complete experimental mode shapes. Results f rom three damaged structures are presented. A 2-bar truss illustrates the basis for the method, a 15-bar truss shows its use with symmetrica l structures, and a redundant-bar truss is used to compare the new met hod with that of Pandey and Biswas. Correct predictions of the locatio n and relative amounts of damage at multiple sites are obtained, even when low damage levels are present in the structure.