EXPERIMENTAL RESULTS IN DETECTION AND LOCALIZATION OF A CHANGE IN A FLEXIBLE STRUCTURE'S DYNAMICS

摘要

Under some general assumptions, the dynamics of a flexible structure are represented by a lumped-parameter model involving matrices of physical parameters, i.e., mass (M), damping (L), and stiffness (K), as well as input and output matrices which can be determined with the knowledge of the placement of sensors and actuators. Such a model is associated with a particular configuration of sensors and actuators. Using frequency-rich input-output time histories (obtained with the same setup of sensors and actuators), the state space representation can be obtained and then the elements of M, L, and K matrices can be estimated. Since these matrices are associated with a fixed set of sensor locations, it is possible to detect the change of the physical parameters (due to the change in a flexible structure's dynamics) associated with these locations. This approach is illustrated in the paper using the measurement data from a simple uniform aluminum cantilever beam.