On the modal diagonalization of viscoelastic mechanical systems. (November 2017)

• Record Type: Journal Article
• Authors: Mastroddi, F.; Eugeni, M.; Erba, F.
• Is Part Of: Mechanical systems and signal processing. Volume 96(2017)
• Page Start: 159
• Page End: 175
• Publication Date: 2017-11
• Subjects: Viscoelasticity -- Hysteretic damping -- Modal analysis -- Finite Element Modelling; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2017.04.009
• Languages: English
• ISSNs: 0888-3270

Abstract

Highlights: FEM equations of a viscoelastic media obtained by first principles of mechanics. Causality of the considered viscoelastic model has been discussed. Modal diagonalization of the viscoelastic space-discretized system is considered. Spectral properties of viscoelastic systems with hysteretic damping are analyzed. Not-space-homogenous hysteretic damping may be equivalent to a non-homogeneous one. Abstract: In this paper the modal coupling of linear viscoelastic oscillators is discussed. In particular, it is demonstrated that in presence of space-homogeneous ideal hysteretic damping, namely, viscoelastic materials with loss factor constant as function of frequency, a set of coupled linear oscillators can be always decoupled by a real coordinate transformation. This result can be extended to the case of a not space-homogeneous ideal hysteretic damping if the modes of vibration of the system keep practically real. The proposed approach is applied to a linear Multi-Degree of Freedom system representing the Finite Element Model of an aeronautical structure.