Near-irreversibility in a conservative linear structure with singularity points in its modal density


Carcaterra A., AKAY A., Koc I.

JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, cilt.119, ss.2141-2149, 2006 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 119 Konu: 4
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1121/1.2179747
  • Dergi Adı: JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
  • Sayfa Sayıları: ss.2141-2149

Özet

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. (c) 2006 Acoustical Society of America.