### Abstract

Fundamental issues relative to structural vibration and to scattering of sound from structures with imprecisely known internals are explored, with the master structure taken as a rectangular plate in a rigid baffle, which faces an unbounded fluid medium on the external side. On the internal side is a fuzzy structure, consisting of a random array of point-attached spring-mass systems. The theory predicts that the fuzzy internal structure can be approximated by a statistical average in which the only relevant property is a function m̄_{F}(Ω) which gives a smoothed-out total mass, per unit plate area, of all those attached oscillators which have their natural frequencies less than a given value Ω. The theory also predicts that the exact value of the damping in the fuzzy structure is of little importance, because the structure, even in the limit of zero damping, actually absorbs energy with an apparent frequency-dependent damping constant proportional to dm̄_{F}(ω)/dω incorporated into the dynamical description of the master structure. A small finite value of damping within the internals will cause little appreciable change to this limiting value.

Original language | English (US) |
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Pages (from-to) | 1-12 |

Number of pages | 12 |

Journal | American Society of Mechanical Engineers (Paper) |

State | Published - Dec 1 1993 |

Event | Proceedings of the ASME Winter Conference - New Orleans, LA, USA Duration: Nov 28 1993 → Dec 3 1993 |

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### All Science Journal Classification (ASJC) codes

- Mechanical Engineering

### Cite this

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**Fundamental structural-acoustic idealizations for structures with fuzzy internals.** / Pierce, Allan D.; Sparrow, Victor W.; Russell, Daniel A.

Research output: Contribution to journal › Conference article

TY - JOUR

T1 - Fundamental structural-acoustic idealizations for structures with fuzzy internals

AU - Pierce, Allan D.

AU - Sparrow, Victor W.

AU - Russell, Daniel A.

PY - 1993/12/1

Y1 - 1993/12/1

N2 - Fundamental issues relative to structural vibration and to scattering of sound from structures with imprecisely known internals are explored, with the master structure taken as a rectangular plate in a rigid baffle, which faces an unbounded fluid medium on the external side. On the internal side is a fuzzy structure, consisting of a random array of point-attached spring-mass systems. The theory predicts that the fuzzy internal structure can be approximated by a statistical average in which the only relevant property is a function m̄F(Ω) which gives a smoothed-out total mass, per unit plate area, of all those attached oscillators which have their natural frequencies less than a given value Ω. The theory also predicts that the exact value of the damping in the fuzzy structure is of little importance, because the structure, even in the limit of zero damping, actually absorbs energy with an apparent frequency-dependent damping constant proportional to dm̄F(ω)/dω incorporated into the dynamical description of the master structure. A small finite value of damping within the internals will cause little appreciable change to this limiting value.

AB - Fundamental issues relative to structural vibration and to scattering of sound from structures with imprecisely known internals are explored, with the master structure taken as a rectangular plate in a rigid baffle, which faces an unbounded fluid medium on the external side. On the internal side is a fuzzy structure, consisting of a random array of point-attached spring-mass systems. The theory predicts that the fuzzy internal structure can be approximated by a statistical average in which the only relevant property is a function m̄F(Ω) which gives a smoothed-out total mass, per unit plate area, of all those attached oscillators which have their natural frequencies less than a given value Ω. The theory also predicts that the exact value of the damping in the fuzzy structure is of little importance, because the structure, even in the limit of zero damping, actually absorbs energy with an apparent frequency-dependent damping constant proportional to dm̄F(ω)/dω incorporated into the dynamical description of the master structure. A small finite value of damping within the internals will cause little appreciable change to this limiting value.

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UR - http://www.scopus.com/inward/citedby.url?scp=0027885696&partnerID=8YFLogxK

M3 - Conference article

AN - SCOPUS:0027885696

SP - 1

EP - 12

JO - [No source information available]

JF - [No source information available]

SN - 0402-1215

ER -