Time-Domain Identification of Structural Systems from Input-Output Measurements

This paper presents a methodology that can be used for the identification of second-order models of structural systems using dynamic measurements of the input and of the structural response. This approach (and its variations) starts from an identified first order model of a structural system and obtain estimation of the structure’s mass, damping and stiffness matrices. For these approaches, both the full instrumentation option and the partial instrumentation option are presented. For the case of partial/limited instrumentation, five different model types have been considered showing, for each models, the limitations imposed on the identification by the lack of available data. Once these dynamic characteristics have been determined, structural damage can be assessed by comparing the undamaged and damaged estimation of such parameters. A damage representative parameter is introduced: this parameter uses the identified models to detect the location and amount of structural damage. This methodology has been tested on simulated numerical results and its effectiveness in determining structural damage is evaluated.