Identification of Modal Parameters with Unknown Input

  • Maurizio De Angelis
  • Vincenzo Sepe
  • Danilo Capecchi
Part of the International Centre for Mechanical Sciences book series (CISM, volume 471)


The techniques developed for structural identification are typically devoted to obtain a structural model on the base of information on the response and on the forcing action. In many situations, however, it can be necessary to refer only to the measured responses. In this paper we describe the theoretical and computational aspects of a technique we have recently developed to identify the modal model in the frequency domain when the input is unknown. We show that this identification problem has an unique solution when at least three responses are known. Anyway, when one of the modal parameters is known, the other ones can be obtained on the base of two responses only. Numerical applications are carried out on plane framed structures ranging from three to eight stories. The modal model may also be incomplete, including only the lowest modes. The results obtained are satisfactory in most cases.


Modal Parameter Unknown Input Ambient Vibration Modal Model Experimental Modal Analysis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Wien 2003

Authors and Affiliations

  • Maurizio De Angelis
    • 1
  • Vincenzo Sepe
    • 2
  • Danilo Capecchi
    • 3
  1. 1.Dipartimento di Ingegneria Strutturale e GeotecnicaUniversity of Rome “La Sapienza”RomeItaly
  2. 2.Dipartimento di Progettazione, Riabilitazione e Controllo delle Strutture ArchitettonicheUniversity of Chieti-Pescara “G. D’Annunzio”PescaraItaly
  3. 3.Dipartimento di Scienza delle CostruzioniUniversity of Naples “Federico II”NaplesItaly

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