Robust change detection method with application in vibration structures monitoring

A signal processing technique for analysing both the transient natural excitations and the vibration structures response, capable of determining the time variations in the amplitude and in the frequency content of these structures, is presented. This technique makes use of an impulse invariant transformation for obtaining an equivalent model of the vibration structure, represented by a parallel-form realization of second-order subsystems, corresponding to different modes of vibration, having as input a stationary independent and identically distributed sequence. The method was applied for detection of changes in dynamic characteristics of a vibrating structure, a multi-story concrete building subject to an earthquake ground motion.