TRANSFER FUNCTION METHOD FOR INVESTIGATING THE COMPLEX MODULUS OF ACOUSTIC MATERIALS: SPRING-LIKE SPECIMEN.

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

The complex modulus of acoustic materials has to be known as a function of frequency. Among many methods for investigating the complex modulus, it is advantageous to use the transfer function method for detailed frequency analysis. In this method, a cylindrical or prismatic specimen is excited into longitudinal vibration at one end, the other end being loaded by a mass. The complex modulus can be calculated after having measured the transfer function: i. e. , the vibration amplitudes of the specimen ends and the phase angle between them. In this paper the transfer function and its measurability are investigated theoretically and experimentally in that frequency range where the specimen can essentially be modeled by lumped parameter mechanical elements. The role of the measurement errors is analyzed and it is shown that the smaller the loss factor the higher the measurement accuracy that is needed. Furthermore, it is shown that disregarding the longitudinal wave motion of the specimen at higher frequencies leads to an apparent increase of the dynamic modulus and to an apparent decrease of the loss factor. This effect may be compensated up to a certain frequency by the lateral wave motion of the specimen. Experimental results supporting the theoretical predictions are presented.

Original languageEnglish
Pages (from-to)317-341
Number of pages25
JournalJournal of Sound and Vibration
Volume72
Issue number3
DOIs
Publication statusPublished - Oct 8 1980

Fingerprint

transfer functions
Transfer functions
Acoustics
acoustics
Measurement errors
vibration
longitudinal waves
phase shift
frequency ranges
predictions

ASJC Scopus subject areas

  • Engineering(all)
  • Mechanical Engineering

Cite this

TRANSFER FUNCTION METHOD FOR INVESTIGATING THE COMPLEX MODULUS OF ACOUSTIC MATERIALS : SPRING-LIKE SPECIMEN. / Pritz, T.

In: Journal of Sound and Vibration, Vol. 72, No. 3, 08.10.1980, p. 317-341.

Research output: Contribution to journalArticle

@article{badc7b8387ef4c7da4bba0e48cff312d,
title = "TRANSFER FUNCTION METHOD FOR INVESTIGATING THE COMPLEX MODULUS OF ACOUSTIC MATERIALS: SPRING-LIKE SPECIMEN.",
abstract = "The complex modulus of acoustic materials has to be known as a function of frequency. Among many methods for investigating the complex modulus, it is advantageous to use the transfer function method for detailed frequency analysis. In this method, a cylindrical or prismatic specimen is excited into longitudinal vibration at one end, the other end being loaded by a mass. The complex modulus can be calculated after having measured the transfer function: i. e. , the vibration amplitudes of the specimen ends and the phase angle between them. In this paper the transfer function and its measurability are investigated theoretically and experimentally in that frequency range where the specimen can essentially be modeled by lumped parameter mechanical elements. The role of the measurement errors is analyzed and it is shown that the smaller the loss factor the higher the measurement accuracy that is needed. Furthermore, it is shown that disregarding the longitudinal wave motion of the specimen at higher frequencies leads to an apparent increase of the dynamic modulus and to an apparent decrease of the loss factor. This effect may be compensated up to a certain frequency by the lateral wave motion of the specimen. Experimental results supporting the theoretical predictions are presented.",
author = "T. Pritz",
year = "1980",
month = "10",
day = "8",
doi = "10.1016/0022-460X(80)90380-6",
language = "English",
volume = "72",
pages = "317--341",
journal = "Journal of Sound and Vibration",
issn = "0022-460X",
publisher = "Academic Press Inc.",
number = "3",

}

TY - JOUR

T1 - TRANSFER FUNCTION METHOD FOR INVESTIGATING THE COMPLEX MODULUS OF ACOUSTIC MATERIALS

T2 - SPRING-LIKE SPECIMEN.

AU - Pritz, T.

PY - 1980/10/8

Y1 - 1980/10/8

N2 - The complex modulus of acoustic materials has to be known as a function of frequency. Among many methods for investigating the complex modulus, it is advantageous to use the transfer function method for detailed frequency analysis. In this method, a cylindrical or prismatic specimen is excited into longitudinal vibration at one end, the other end being loaded by a mass. The complex modulus can be calculated after having measured the transfer function: i. e. , the vibration amplitudes of the specimen ends and the phase angle between them. In this paper the transfer function and its measurability are investigated theoretically and experimentally in that frequency range where the specimen can essentially be modeled by lumped parameter mechanical elements. The role of the measurement errors is analyzed and it is shown that the smaller the loss factor the higher the measurement accuracy that is needed. Furthermore, it is shown that disregarding the longitudinal wave motion of the specimen at higher frequencies leads to an apparent increase of the dynamic modulus and to an apparent decrease of the loss factor. This effect may be compensated up to a certain frequency by the lateral wave motion of the specimen. Experimental results supporting the theoretical predictions are presented.

AB - The complex modulus of acoustic materials has to be known as a function of frequency. Among many methods for investigating the complex modulus, it is advantageous to use the transfer function method for detailed frequency analysis. In this method, a cylindrical or prismatic specimen is excited into longitudinal vibration at one end, the other end being loaded by a mass. The complex modulus can be calculated after having measured the transfer function: i. e. , the vibration amplitudes of the specimen ends and the phase angle between them. In this paper the transfer function and its measurability are investigated theoretically and experimentally in that frequency range where the specimen can essentially be modeled by lumped parameter mechanical elements. The role of the measurement errors is analyzed and it is shown that the smaller the loss factor the higher the measurement accuracy that is needed. Furthermore, it is shown that disregarding the longitudinal wave motion of the specimen at higher frequencies leads to an apparent increase of the dynamic modulus and to an apparent decrease of the loss factor. This effect may be compensated up to a certain frequency by the lateral wave motion of the specimen. Experimental results supporting the theoretical predictions are presented.

UR - http://www.scopus.com/inward/record.url?scp=0019319703&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019319703&partnerID=8YFLogxK

U2 - 10.1016/0022-460X(80)90380-6

DO - 10.1016/0022-460X(80)90380-6

M3 - Article

AN - SCOPUS:0019319703

VL - 72

SP - 317

EP - 341

JO - Journal of Sound and Vibration

JF - Journal of Sound and Vibration

SN - 0022-460X

IS - 3

ER -