Showing papers in "Journal of Sound and Vibration in 1970"

TL;DR: In this paper, a 3D linear, small deformation theory of elasticity solution by the direct method is developed for the free vibration of simply-supported, homogeneous, isotropic, thick rectangular plates.

TL;DR: In this paper, the authors considered the free harmonic motion of infinite beams on identical, equi-spaced supports and derived the flexural propagation constants for beams on rigid supports which exert elastic rotational restraint.

TL;DR: In this article, the authors discussed the nature of damping mechanisms and how the damping depends on the amplitude and frequency of the cyclic motion of the system. But they did not consider the effect of the frequency and amplitude on damping.

TL;DR: The problem of establishing the correspondence between the discrete transforms and the continuous functions with which one is usually dealing is described and formulas and empirical results displaying the effect of optimal parameters on computational efficiency and accuracy are given.

TL;DR: In this paper, a unified theory for spectral description, convolution, and filtering on non-stationary stochastic processes is presented, which deals with the spectral description and convolutional filtering of nonstationary processes.

TL;DR: In this article, the free vibration of beams and plates over supports at regular intervals has been analyzed using the knowledge of natural flexural waves and the associated propagation constants, and it has been shown that the conditions at the extreme ends of a finite, periodic structure, permit only certain discrete values of the propagation constant.

TL;DR: In this article, a variety of analytical approximations to p1(T) dT for the linear oscillator are described and compared with results obtained by simulation and numerical methods, where the mean time to passage is very long in comparison with the natural period of the oscillator.

TL;DR: In this article, the authors used the differential equation for the damped normal modes of a three-layer encastre sandwich beam, in conjunction with appropriate boundary conditions, to determine the characteristic equation for resonant frequency, loss factor and modal roots.

TL;DR: In this paper, a polynomial system is defined as a system that carries a signal of the form X 1 ( t ) + αX 2 ( t ), − ∞ t.

TL;DR: In this article, a solution for forced vibration transmission was found which does not require the arbitrary assumption usually made in estimating this type of transmission from the solution for an infinite partition, but is in at least as good agreement with experiment.

TL;DR: In this paper, the effect of blade spacing on sound propagation through a blade row with finite blade spacing is investigated theoretically, in which the kernel function of the aerodynamic integral equation is expressed by several series of the exponential functions, under which many circumferential modes propagate as the transmitted wave and reflected wave for one mode of incident waves.

TL;DR: A theoretical study of the interaction between finite-amplitude sound and a single Helmholtz resonator is presented in this paper, where flows in the entrance region, orifice and cavity have been considered in detail with the aid of the appropriate conservation equations.

TL;DR: In this paper, individual loudness functions have been obtained by a form of magnitude estimation for 15 observers over a period of five months and used two different procedures, and the results show that most of the individual observers can produce a loudness function of consistent slope and in many cases this slope is significantly different from the mean slope of the group.

TL;DR: In this article, the transmission and reflection coefficients of axial-flow compressor ducts were studied theoretically using semi-actuator disk theory, and the effects of flow Mach number, angle of incidence, wavelength and stagger angle on sound propagation were investigated.

TL;DR: In this article, the rotor-stator interaction was studied theoretically, taking into account the effect of compressibility of fluid and the non-compact source distribution over the blades.

TL;DR: In this article, the spectrum of a continuous-time series of events (point stochastic process) is derived by smoothing the periodogram and the spectrum is then used to estimate the phase and amplitude of the intensity function.

TL;DR: In this article, an analysis of axisymmetric and unsymmetric free vibrations of conical or cylindrical shells with various boundary conditions is presented, where Love's first-approximation shell theory, with transverse shear strain added, was used and solutions were obtained by Galerkin's method.

TL;DR: In this article, the authors considered the reflection and transmission of plane harmonic waves in a flowing medium, by an infinite set of flat plates of arbitrary spacing and stagger, and the problem of solving this equation subject to the pertinent boundary conditions is converted into two consecutive Wiener-Hopf problems.

TL;DR: In this article, a simple extension of the Powell's frequency formula to the flight case is presented, and a correlation of the results obtained so far is discussed, and the first in-flight occurrences of shock cell noise that were recognized as such took place some ten or more years later, in the early 1960's.

TL;DR: In this article, it was shown that the unconstrained layer technique can be equal in damping effectiveness to the four-layer beam construction with the same total thickness of damping layers only when the modulus of elasticity of the non-constraint layer is of the same order of magnitude as for metals.

TL;DR: In this paper, the finite element method was used to investigate the natural frequencies and mode shapes of thin circular cylindrical shells with stiffening rings, where each stiffening ring was treated as a discrete element.

TL;DR: In this article, the authors discuss pressure wave effects, energy flux and boundary conditions of an internal combustion engine exhaust system sound radiation, discussing pressure wave and energy flux effects, and the boundary conditions.

TL;DR: In this paper, the natural frequencies of thin cantilever cylindrical shells are determined, directly from a solution of Flugge's equations of motion and also approximately, using the Rayleigh-Ritz method.

TL;DR: Perturbation method to obtain analytical expressions for attenuation of plane wave sound propagation in lined ducts is presented in this article, where it is shown that attenuation attenuates plane wave propagation in line ducts.

TL;DR: Alternative methods for the estimation of spectra are described and compared and general questions of statistical variability, the use of regression methods to smooth the periodogram, and use of time sectioning of the data to either smooth or to investigate non-stationarities in the data are discussed.

TL;DR: In this paper, the authors investigated the sound absorption properties of ground surfaces and developed a method for field measurement of the acoustic impedance of the ground surface using free wave reflection (FWR) method.

TL;DR: In this paper, the Curle theory of dipole radiation for the Aeolian tone holds for a cylinder resonantly excited by a periodic wake in air, and the increase of the oscillating lift coefficient with Reynolds number accounts for the increase in sound intensity.

TL;DR: In this article, the first symmetric and first antisymmetric modes of a simplysupported rectangular plate are determined by the Ritz method using a two-term solution, for a wide range of ratios of (a/b ) and (stiffener depth/plate thickness).