Showing papers in "Journal of Sound and Vibration in 1979"

TL;DR: In this paper, the authors presented experimental evidence for chaotic type non-periodic motions of a deterministic magnetoelastic oscillator, analogous to solutions in non-linear dynamic systems possessing what have been called "strange attractors".

TL;DR: A finite element formulation of the equations governing the laminated anisotropic plate theory of Yang, Norris and Stavsky, is presented in this article, which is a generalization of Mindlin's theory for isotropic plates to laminated aisotropic plates and includes shear deformation and rotary inertia effects.

TL;DR: In this article, the effects of the root radius, the setting angle and the tip mass are incorporated into the finite element model to investigate the vibration frequency of a rotating beam with tip mass.

TL;DR: In this article, the response of a single degree of freedom spring-mass system with viscous and Coulomb friction, with harmonic base excitation, was determined, and closed form analytical solutions of the equation of motion were found for two cases: (a) continuous motion of the mass and (b) motion of mass with two stops per cycle.

TL;DR: In this article, a theoretical analysis for the harmonic noise of high speed, open rotors is presented, where the dominant sources are the volume displacement and the ϱu2 quadrupole, where u is the disturbance velocity component in the direction of blade motion.

TL;DR: In this article, a noise source is identified in a cold jet at M = 0·98 by using the causality method proposed by Ribner and Siddon, which includes measuring the correlations between the velocity fluctuations inside the jet (these velocity fluctuations are measured by means of a laser velocimeter) and the far field acoustic pressure.

TL;DR: A second order beam theory which takes into account shear curvature, transverse direct stresses and rotatory inertia is presented in this article, where the governing differential equation is similar in form to the Timoshenko beam equation but contains two coefficients, one of which depends on cross-sectional warping just as does Cowper's expression while the second includes terms dependent on the transversal direct stresses.

TL;DR: An experimental investigation of noise generation by instabilities in low Reynolds number supersonic air jets has been performed by Morrison and McLaughlin this paper, where sound pressure levels, spectra and acoustic phase fronts were measured with a traversing condenser microphone in the acoustic field of axisymmetric, perfectly expanded, cold jets.

TL;DR: In this article, the free vibration of skew plates by the Rayleigh-Ritz method with B-spline functions as co-ordinate functions was investigated and convergence of the solutions was investigated in a few typical cases and was found to be satisfactory.

TL;DR: In this paper, the amplitude and phase of the disturbances corresponding to small amplitude fluctuations in the heat addition are calculated by idealizing combustion or heat addition processes to occur over a short distance in the flow direction.

TL;DR: The interfaces of the grains are coated with inert, slow-burning material as discussed by the authors, and the inert material is exposed in the form of annular rings oriented normal to the axis of the chamber.

TL;DR: In this article, the authors considered the problem of determining those free waves of the coupled system which can actually be excited by external forces, with the aim of determining the free wave of a fluid-loaded thin elastic plate.

TL;DR: In this article, a procedure is developed for simulating the dynamic interaction between traversing vehicles and structures, where Lagrange multipliers are employed in time to satisfy constraint conditions between the systems.

TL;DR: In this paper, the authors present a method for estimating A-weighted sound levels as well as noise and vibration spectra due to ground-transmitted vibration in buildings near subways.

TL;DR: Theoretical and experimental results for the transverse driving point mechanical impedances, as well as for the transfer impedances of damped composite plates made up of a thin viscoelastic layer sandwiched between two elastic layers are presented and discussed in this article.

TL;DR: In this paper, an energy method has been developed to predict the frequency of wave propagation in terms of the propagation constants, and it has been shown that the propagation bands can overlap.

TL;DR: In this paper, the sound intensity of jet noise from aircraft in flight is derived in a co-ordinate system fixed to the jet engine and a convected form of the Lighthill equation is solved with special care taken of jet temperature effects.

TL;DR: In this paper, a second-order perturbation theory is developed for the response of slightly damped gyroscopic systems, based on the eigensolution for undamped systems and expressed in terms of real quantities alone.

TL;DR: In this paper, the authors proposed a method for determining the radial mode distribution of the distortion generated noise of an isolated fan in an annular or circular duct, where the circumferential analysis is simply a Fourier transform, but the radial analysis is in terms of Bessel functions.

TL;DR: In this paper, Fourier transforms of transient pressure data are used to provide system characteristics in the frequency domain and derive matrix parameters expressed in terms of the transforms of pairs of pressure data for a variety of testing conditions and system types.

TL;DR: In this article, a study was conducted to identify the dynamic characteristics of freely vibrating human skulls in the frequency band from 20 Hz to 5000 Hz for two dry human skulls, one representing a 50th percentile male skull and the other representing a 5th percentile female skull.

TL;DR: In this paper, a mathematical model was presented for the transmission of airborne noise through the walls of an orthotropic cylindrical shell, and parameters were varied to see how orthotropicity affected noise transmission.

TL;DR: In this article, the effects of non-linearities on the resonant vibrations of multi-degree-of-freedom systems (lumped parameter or continuous ones) were studied and the results obtained are compared to those produced by the commonly used classical single mode method.

TL;DR: In this paper, a theoretical and experimental study of self-induced nonplanar vibrations of a flexible tube conveying a fluid is made, where the tube is fixed at one end and the fluid issues from a nozzle inclined to the axis of the tube at the free end.

TL;DR: In this article, the authors presented two finite element models for the prediction of free vibrational natural frequencies of fixed-free beams of general orthotropy, including the transverse shear deformation effect and the rotary inertia effect.

TL;DR: In this article, the stability of viscoelastic beams with an attached mass and end supports under axial and tangential periodic loads is investigated, and the regions of instability for simple and combination resonances are obtained from the ordinary Mathieu equation.

TL;DR: In this paper, the stapedius muscle is included as an explicit functional unit and the acoustical characteristics of the external ear canal are also included, and the model is extensively evaluated by comparing its properties with the known characteristics of real ears of humans and other animals.

TL;DR: In this paper, the stiffness, mass and gyroscopic matrices of a rotating beam element are developed, a cubic function being used for the transverse displacement, and rotatory inertia effects are included in the energy functional to provide a Timoshenko beam formulation.

TL;DR: In this paper, a finite element method is used to formulate the eigenvalue problem for a lined duct with flow, and the primitive variables of velocity and pressure are used with quadratic shape functions in each element.

TL;DR: This paper examined the residual problems of ground-borne vibration, the vehicle and track features which might be responsible for generation, how it is propagated, and how it might affect wayside buildings.