Showing papers in "Journal of Sound and Vibration in 1997"

TL;DR: In this article, a boundary integral formulation is presented for the evaluation of the noise radiated in a uniform medium by generic sources, which is referred as the Kirchhoff-FWH method.

TL;DR: In this article, a curve-fitting cross-correlation function between two response measurements made on an ambiently excited structure is shown to have the same form as the system's impulse response function.

TL;DR: In this article, a technique for identifying the location of structural damage in a beam is presented, which operates solely on the mode shape from the damaged structure, and does not require a prior knowledge of the undamaged structure.

TL;DR: In this article, the novelty detection method was applied to diagnose damage in a simple simulated lumped-parameter mechanical system and it was shown that the system transmissibility provided a sensitive feature for the detection of small stiffness changes.

TL;DR: In this paper, a method of damping identification in multi-degree-of-freedom systems is presented based on the time-scale decomposition of the system impulse response, where the continuous wavelet transform is used to decompose the impulse response into the timescale domain.

TL;DR: In this paper, an analytical model has been proposed for predicting the vibration frequencies of rolling bearings and the amplitudes of significant frequency components due to a localized defect on outer race, inner race or on one of the rolling elements under radial and axial loads.

TL;DR: In this article, a solution for the vertical dynamic interaction forces between a moving vehicle and the bridge deck is analytically derived and experimentally verified, where the deck is modeled as a simply supported beam with viscous damping, and the vehicle/bridge interaction force is modelled as one point or two-point loads with fixed axle spacing, moving at constant speed.

TL;DR: It is found that, for the structural and boundary layer parameters typical of transport aircraft, the contributions of resonant, acoustically inefficient plate modes dominate the radiated power.

TL;DR: In this paper, a piecewise-linear two-degree-of-freedom model of a cantilever beam with a transverse edge crack is considered and a bilinear frequency is defined for each of the linear pieces of the piecewise linear system.

TL;DR: In this paper, a two-dimensional model of human biomechanical responses to whole-body vibration has been developed, by using the finite element method, using Beam, spring and mass elements to model the spine, viscera, head, pelvis and buttocks tissue.

TL;DR: In this paper, a method is presented which uses the modal parameters of the lower modes for the non-destructive detection and sizing of cracks in beams using a finite element model of the structure.

TL;DR: In this paper, a method based on measurement of natural frequencies is presented for detection of the location and size of a crack in a stepped cantilever beam, where the crack is represented as a rotational spring and the method involves obtaining plots of stiffness with crack location for any three natural modes through the characteristic equation.

TL;DR: In this paper, the authors investigated the dynamic response of an axially accelerating string, where the time dependent velocity is assumed to vary harmonically about a constant mean velocity, and they found that instabilities occur when the frequency of velocity fluctuations is close to two times the natural frequency of the constant velocity system or when the frequencies are close to the sum of any two natural frequencies, but no instabilities are detected up to the first order of perturbation.

TL;DR: In this article, a tunable Helmholtz resonator and a novel feedback based control law were proposed to achieve optimal tuning of the resonator for time varying tonal noise control applications.

TL;DR: In this article, the authors investigate the aeroacoustic generation mechanism of the tip clearance noise in axial turbomachines and show that the noise is associated with a rotating source or vortex mechanism which moves relative to the blade row at a fraction of the impeller shaft speed, similar to the cell(s of rotating stall.

TL;DR: In this article, a time domain non-parametric method for non-linear vibration system identification based on the Hilbert transform is introduced, which is demonstrated using computer simulations of different types of nonlinear elastic and damping dynamic systems.

TL;DR: In this paper, three closely related models for two-layered beams in which slip can occur at the interface are described, and the optimal damping rates are calculated for these low frequency motions.

TL;DR: In this paper, the explicit formulations for computing the weighting coefficients in the harmonic differential quadrature have been developped, and the solution of a differential equation is approximated by a Fourier series expansion.

TL;DR: In this paper, an exact dynamic stiffness element under the frame work of finite element approximation is presented to study the dynamic response of multi-span structures under a convoy of moving loads.

TL;DR: It is stated that this new trigonometric set can be used at very high orders without taking care of computer round-off errors, while the polynomials set fail, at order 46 because of the limited numerical dynamics of computers.

TL;DR: In this paper, active and passive means are combined for the design of locally controlled absorption liners in air, whose basic principles were described by Olson and May and subsequently investigated practically by Guicking and his colleagues at the beginning of the 80's.

TL;DR: In this paper, the performance of multiple tuned mass dampers (MTMD) for suppressing the dynamic response of a base-excited structure in a specific mode is investigated, where the base excitation is modelled as a stationary white noise random process.

TL;DR: In this article, a pilot study was carried out to assess method evaluating effects of low frequency noise on performance, and subjective and objective effects over time were studied over a period of three weeks.

TL;DR: In this paper, the conventional harmonic probing algorithm of Bedrosian and Rice can be extended to deal with the multi-input multi-output form of the Volterra functional series.

TL;DR: In this paper, the authors investigated the effect of the length of the expansion chamber on the acoustic attenuation performance of concentric expansion chambers and provided a simple relation for the number of repeating attenuation domes prior to the domination of higher order modes.

TL;DR: In this article, exact analytical solutions for the longitudinal vibration of rods with non-uniform cross-section were presented for a rod with a polynomial area vibration and for a sinusoidal rod.

TL;DR: In this article, a beam grillage system is analyzed by using the hierarchical finite element method to model a single period and then employing periodic structure theory to yield the "phase constant surfaces" which are needed for the forced response analysis.

TL;DR: In this article, the authors used the singular value decomposition (SVD) of a general Hankel matrix to identify successive discrete transition matrices that have the same eigenvalues as the original transition matrix.

TL;DR: In this article, the first fifteen natural frequencies of vibration are calculated for uniform circular plates with free, simply-supported and clamped edges, and the capability and simplicity of the differential quadrature method for moderately thick plate eigenvalue analysis is demonstrated.

TL;DR: In this paper, a dynamic model for the axial and transverse vibrations of a rotating drillstring is presented, where the governing non-linear equations are obtained by using a Lagrangian approach with time varying coefficients.