Complex-damped dynamic systems in the time and frequency domains

Issue title: Dedicated to Professor Bruno Piombo

Article type: Research Article

Authors: Bonisoli, Elvio | Mottershead, John E.

Affiliations: Politecnico di Torino, Dipartimento di Meccanica, Corso Duca degli Abruzzi, 24 - 10129, Torino, Italy | The University of Liverpool, Department of Engineering, Mechanical Engineering Division, Brownlow Hill, Liverpool L69 3GH, England, UK

Note: [] Corresponding author. Tel.: +39 011 564 6947; Fax: +39 011 564 6999; E-mail: elvio.bonisoli@polito.it

Abstract: The fact that a complex-damped model may represent the dynamic behaviour of elasto-mechanical systems when acted upon by a magnetic field was brought to the attention of the structural dynamics community very recently by Professor Bruno A. D. Piombo and his colleagues at the Politecnico di Torino. In this paper a thorough analysis of the single degree-of-freedom complex-damped mass-spring system is presented. The analysis includes the root locus, the (non-causal) impulse response, the frequency response and the transmissibility. Regions of different behaviour in the frequency response and transmissibility are described in detail. The stiffening behaviour observed in Prof. Piombo's experiments and known as the "phantom effect" is demonstrated by the complex-damped model.

Journal: Shock and Vibration, vol. 11, no. 3-4, pp. 209-225, 2004