Accession Number:

ADA076772

Title:

Transient Acoustic Radiation from Elastic Plates.

Descriptive Note:

Doctoral thesis,

Corporate Author:

PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB

Personal Author(s):

• Sengerdy,Seroj Mackertich

Report Date:

1979-04-02

Pagination or Media Count:

112.0

Abstract:

An expression for the acoustic radiated pressure emanating from an infinite elastic plate excited by a unit impulse laod for different observation angles and distances is obtained analytically. The solution is obtained by use of Fourier transform on time and Hankel transform on the radial coordinate. Using Cauchy contour integration theorem and regular and modified saddle-point methods, the inverse Fourier and Hankel transforms were evaluated. The unit impulse response and convolution theorem was then utilized to obtain an expression for radiated pressure of an infinite elastic plate excited by constant magnitude load, square pulse and CW-pulse loads. The first arrival of acoustic wave at an observer point in the acoustic medium due to an impulse load was shown to correspond to the time of travel for the normal distance from the observer to the plate. After the first arrival, the acoustic pressure was shown to decay sinusoidally with an increasing period of oscillation. The decay rate for long times was shown to be the reciprocal of elapsed time. Similar response was shown for a square pulse and for a CW-pulse after the removal of the load. Author

Descriptors:

• *ACOUSTIC WAVES
• *PLATES
• FOURIER TRANSFORMATION
• TRANSIENTS
• LOADS(FORCES)
• ELASTIC PROPERTIES
• FOURIER ANALYSIS
• CONVOLUTION INTEGRALS

Subject Categories:

• Numerical Mathematics
• Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE