Determination of Stiffness Changes from Modal Parameter Changes for Structural Health Monitoring

A Bayesian probabilistic methodology is presented for identification of structural stiffness loss from changes in estimated modal parameters. The method constitutes the second step of a two-step procedure for continuously monitoring the health of a structure by utilizing its natural ambient vibrations. The version presented here assumes that any damage that occurs is localized to one part of the structure. Numerical testing of the proposed scheme shows that under specified conditions, the method successfully determines the existence, location, and degree of stiffness loss, even in the presence of levels of uncertainty in the estimated modal parameters that are expected in real applications.