title: Near-irreversibility in a conservative linear structure with singularity points in its modal density.
abstract: Through two complementary approaches, using modal response and wave propagation, the analyses presented here show the conditions under which a decaying impulse response, or a nearly irreversible energy trapping, takes place in a linear conservative continuous system. The results show that the basic foundation of near-irreversibility or apparent damping rests upon the presence of singularity points in the modal density of dynamic systems or, analogously, in the wave-stopping properties associated with these singularities. To illustrate the concept of apparent damping in detail, a simple undamped beam is modified to introduce a singularity point in its modal density distribution. Simulations show that a suitable application of a compressive axial force to an undamped beam placed on an elastic foundation attenuates its impulse response with time and develops the characteristics of a nearly irreversible energy trap.
authors.affiliation: Department of Mechanics and Aeronautics, University of Rome, La Sapienza Via Eudossiana, 18, 00184, Rome, Italy. a.carcaterra@dma.ing.uniroma1.it
authors.forename: A
authors.initials: A
authors.lastname: Carcaterra
authors.forename: A
authors.initials: A
authors.lastname: Akay
authors.forename: I M
authors.initials: IM
authors.lastname: Koç