Showing papers in "Journal of Sound and Vibration in 1981"

TL;DR: In this paper, a two-dimensional airfoil embedded in a uniform low Mach number flow is examined by applying several TE noise theories to the measured data, and the TE noise spectra and directivity are quantitatively determined for the case of a high Reynolds number and a fully turbulent boundary layer.

TL;DR: In this paper, a new theory for beams of rectangular cross-section which includes warping of the cross-sections is presented, and results for two typical static examples are given for both the new theory and Timoshenko beam theory.

TL;DR: In this article, an extensive series of experiments were conducted with a simulation system to investigate the determinants of the subjective effect created by early lateral reflections, which is called here "spatial impression".

TL;DR: In this paper, the authors show that the principal disadvantage of the non-symmetric coefficient matrices can be removed merely by reformulating the pressure solution approach so that a velocity potential rather than pressure is used as the fundamental unknown in the fluid region.

TL;DR: In this paper, a general analytical method is presented for evaluating the free vibration characteristics of a circular cylindrical shell with classical boundary conditions of any type, and the solution is obtained through a direct solution procedure in which Sanders' shell equations are used with the axial modal displacements represented as simple Fourier series expressions.

TL;DR: In this article, the critical velocities of cylinders supported by elastic spars were calculated by using the measured unsteady fluid dynamic forces, which are induced by the vibrating cylinders.

TL;DR: In this article, a full experimental investigation of a flow excited Helmholtz resonator is described, in which the detailed fluid dynamical and acoustic data necessary to develop a mathematical model for the flow was obtained, and a new theory of the interaction process was presented.

TL;DR: In this paper, the authors applied the frequency locus method to the optimization of the spring and damper rates for a dynamic vibration absorber, and derived a tuning function which enables the optimal natural frequency for the absorber to be determined.

TL;DR: In this paper, the power transmission from a vibrating machine to the seating structure via spring-like vibration isolators is investigated, where the low frequency range is considered where the machine moves as a rigid body.

TL;DR: In this article, a sound power spectra of spoiler aerodynamic noise, generated in a low velocity flow duct and radiated from an open exhaust termination, was made in the form of sound power spectrum.

TL;DR: In this article, a critical assessment of the state of the art for flow induced vibrations of cylinder arrays in cross and axial flow is presented, with the aid of a new classification of the flow induced vibration phenomena involved.

TL;DR: In this paper, the steady state relative motion of two masses with dry (Coulomb) friction contact is investigated, where the bodies are assumed to have the same mass and stiffness and are subjected to harmonic excitation.

TL;DR: In this paper, it was shown that period doubling bifurcations to period two can be either sub- or supercritical, depending upon the excitation frequency and damping amplitude.

TL;DR: In this paper, the transmission of flexural type waves through various discontinuities in the walls of cylindrical shells is investigated, and theoretical curves of transmission loss are obtained for different circumferential wave types, as functions of frequency.

TL;DR: In this article, a linear beam element with independent displacement fields and reduced integration to eliminate shear locking is used and enables one to detect the second spectrum accurately, which helps to identify and classify the frequencies into two separate spectra.

TL;DR: In this paper, the radiation of sound from infinite fluid loaded plates is examined when the plates are reinforced with two sets of orthogonal line stiffeners and the stiffeners are assumed to be equally spaced and exert only forces on the plate.

TL;DR: In this paper, the scattering of Rayleigh waves by a two-dimensional sub-surface crack, which is perpendicular to the free surface of an elastic half-space, is investigated.

TL;DR: The first step in the process appears to be the development of an ordered train of vortices in the shear layer produced by a separating flow as mentioned in this paper, which can excite resonators strongly.

TL;DR: In this paper, the energy balance equations were used to explain the average behavior of reasonably large constructions, especially with respect to inhomogeneous walls and multiple walls of finite size.

TL;DR: In this article, a new analytical approach to the investigation of the regions of instability of multiple-degree-of-freedom parametric dynamic systems is presented, based on the harmonic balance method.

TL;DR: In this article, a comparison between attenuations obtained, expressed as differences in equivalent constant A-weighted sound pressure levels, showed no significantly higher attenuation values for propagation through belts of trees than for propagation above grass-covered ground.

TL;DR: In this paper, the authors presented accurate non-dimensional frequency parameters for wide ranges of aspect ratio, shallowness ratio and thickness ratio for shallow shells, based on shallow shell theory.

TL;DR: In this article, a finite element scheme based on both the Galerkin method and the residual least squares method with eight noded isoparametric elements is described for the solution of the problem of acoustic transmission through a non-uniform duct carrying a high speed subsonic compressible flow.

TL;DR: In this paper, the fundamental frequency coefficient for a rectangular plate with edges elastically restrained against both translation and rotation is calculated by using polynomial coordinate functions and the Rayleigh-Ritz method.

TL;DR: In this article, a simple repeated impact process similar to the classical random walk process is analyzed, which consists of a ball bouncing on a randomly vibrating surface, is analogous to loss-of-contact situations which can occur in linkages and vibrating tools.

TL;DR: In this paper, a method for localizing and evaluating the transmission paths of any signal in a "black box" among a set of points previously defined in it is presented. But this method requires that the signal should behave linearly and the system should be able to receive external excitations separately at each of its points.

TL;DR: In this paper, the sound field produced when a spherical sound wave is incident on a rigid many-sided barrier or pillar is calculated on the basis of Keller's geometrical theory of diffraction, Kouyoumjian and Pathak's asymptotic solution for a single wedge, and Pierce's method for a doubly diffracted wave.

TL;DR: In this paper, an indirect experimental method for the determination of the modal density and loss factor of simple structures such as a plate and a cylinder is presented, where good agreement is shown to exist in these cases.

TL;DR: In this article, a series-type method was applied to the free vibration of an orthotropic rectangular plate with mixed boundary conditions, where one, two or three parts are constrained along the boundary of the square plate, and the effects of varying constraint and orthotropic parameters on the natural frequencies and mode shapes were studied.