Further understanding of doorway states in elastic systems

• DOI: 10.1121/1.4996500
• Publication Date: 2017-08-07T15:32:31Z
• Authors: J. A. Otero; G. Monsivais; A. Morales; L. Gutiérrez; A. Díaz-de-Anda; J. Flores
• Keywords: 0103 physical sciences; 01 natural sciences

In a previous work an elastic bar with a groove or notch that presents a doorway state was studied when the system was excited with 20 cycles of harmonic signals. The strength function had a Lorentzian width Γd = 1/πτd, where τd is the decay time of the prompt response. In the present paper, the doorway-state phenomenon is analyzed again for the same harmonic signals but for a very large number of cycles. The strength-function phenomenon is once more obtained, but now with a Lorentzian width Γ′ which is larger than Γd. A qualitative and numerical explanation of this fact is given, leading therefore to further understanding of doorway states in elastic systems. The numerical results show a very good agreement with the values measured in the laboratory.