Design criteria for the damping effectiveness of structural fuzzies

Abstract

A rudimentary statistical energy analysis (SEA) of a structural fuzzy reveals that an adjunct structure, i.e., the ‘‘fuzz’’ in a structural fuzzy, attached to a master structure for the purpose of increasing the loss factor of the union, in the range of frequency of concern, is required to satisfy three design criteria. A brief statement of these design criteria is made. An analytical rendition is also presented to give the statement qualitative definition and assessment. Possible noise control issues impacting the performance of structural fuzzies are raised.

Dependence of the induced loss factor on the coupling forms and coupling strengths: energy analysis

“…Simultaneously, a typical loss factor rf{y) of the satellite oscillator need be maintained in excess of TJ^ (y). This condition ensures that the dampings in the satellite oscillators can handle the excess in the stored energy that they are designed to harbor [7]. This handling needs to exceed that which is indigenous to the master oscillator, and hence the criterion stated in Eq.…”

“…must be simultaneously satisfied [7]. The first of these criteria, then, demands that the induced loss factor rf os {y) exceeds the loss factor rj^y) of the isolated master oscillator.…”

“…(6), (7), (22), (30) and (37)-(39) [7,17]. It is recalled that 3*00 is the ratio of the energy stored in the satellite oscillator and in the couplings to the energy stored in the master oscillator.…”

“…(31b), the energy E os (y) stored in the satellite oscillators and in the couplings need be in excess of the energy E 0 (y) stored in the master oscillator. This is achieved by increasing the coupling parameters and the modal density (number of satellite oscillators per unit frequency) of the satellite oscillators [7]. Simultaneously, a typical loss factor rf{y) of the satellite oscillator need be maintained in excess of TJ^ (y).…”

“…Often one tends, in this assessment, to argue that the external input power ratio P°(y) is largely equal to unity [7]. Using Eq.…”