Accession Number : ADA125875


Title :   Computation of Propagation Speed and Reflection of Axially Symmetric Waves in Composite Cylinders, with Application to Impedance Tube and Calibrator.


Descriptive Note : Memorandum rept.,


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC


Personal Author(s) : Dubbelday,Pieter S ; Ruggiero,Clementina M


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a125875.pdf


Report Date : 25 Aug 1982


Pagination or Media Count : 77


Abstract : Waveguide theory is applied to the interpretation of data on reflection and propagation of sound in a water-filled impedance tube and in an acoustic calibrator. Computer programs are described and documented that: relate propagation speed and attenuation for the sample in the impedance tube to the complex reflection coefficient; relate propagation speed in the sample in the impedance tube to the elastic moduli of the sample material, both real and complex; and compute the propagation speed in the acoustic calibrator. A correction factor is developed to account for the lack of rigidity of the reflector in the impedance tube. The major conclusion with respect to the data reduction for the impedance tube is the observation that the relevant wave speed is not necessarily the dilatational wave speed, but is a function of the space between sample and tube wall. By modifying the experimental arrangement one may measure two separate elastic moduli. (Author)


Descriptors :   *ACOUSTIC WAVES , *COMPOSITE STRUCTURES , *WAVE PROPAGATION , *CYLINDRICAL BODIES , VELOCITY , COMPUTER PROGRAMS , COMPUTATIONS , THEORY , ELASTIC PROPERTIES , MODULUS OF ELASTICITY , SHELLS(STRUCTURAL FORMS) , REFLECTION , COEFFICIENTS , ATTENUATION , CALIBRATION , IMPEDANCE


Subject Categories : Laminates and Composite Materials
      Acoustics


Distribution Statement : APPROVED FOR PUBLIC RELEASE