Showing papers in "Mechanical Systems and Signal Processing in 1991"

TL;DR: In this article, the impulse response function of an oscillator with a fractional derivative damping model is integrated with a new efficient technique using the inverse Fourier transform, this requires a unique definition of the constitutive equation in the frequency domain.

TL;DR: In this article, a method for measuring the scattering-matrix of an acoustical two-port is presented and tested, where the basis for the method is a direct estimation of the state vectors.

TL;DR: The Wigner distribution can be interpreted as a distribution of signal energy in both frequency and time domains, which can be applied to the description of machine conditions and is an effective method in machinery fault diagnosis as discussed by the authors.

TL;DR: In this article, an improved piezoelectric finite element with internal degree of freedom is proposed for structural identification and control of distributed parameter systems (DPSs) and a state variable transformation of the dynamic equation is presented.

TL;DR: In this paper, a new modal testing method is proposed for modal parameter identification of rotating machinery and compared with the classical method, which is essentially based on the use of complex notation which has been known to be a powerful mathematical tool in the analysis of rotor systems.

TL;DR: Results based on simulated systems, the prediction of Canadian lynx data, and the modelling of an automotive diesel engine indicate that the recursive prediction error algorithm is far superior to backpropagation.

TL;DR: Simulated and physical experiments are conducted to illustrate the application of two techniques to the estimation of stiffness, damping and mass matrices from vibrations measured from a clamped-clamped beam.

TL;DR: In this paper, the authors defined faults as physical parameter modifications which influence the dynamic behaviour of the structure under consideration, taking into account a change in the number of degrees of freedom of the model.

TL;DR: In this article, the authors proposed an identification scheme for linearised joint parameters of a structure, which makes use of not only the measured frequency response functions (FRFs) of the structure but also the computed FRFs of an auxiliary model.

TL;DR: In this article, a signal processing method to detect flaws in a ball bearing system is proposed, which is formulated theoretically and the performance of the method is expressed in terms of signal to noise ratios.

TL;DR: In this article, a high frequency version of the coin-tap method of non-destructive testing has been investigated, which involves tapping the structure with a very light striker of mass typically below 1 g and monitoring the sound produced by the tap.

TL;DR: In this paper, the rotational FRF of two structures connected together is determined from the translational measured FRF through a finite difference computation, but errors in measurements and noise problems seriously affect the derived quantities and lead to inefficient estimates, and the results obtained for the assembled system following implementation of these actions are quite satisfactory.

TL;DR: It was shown that the Pareto distribution can be used and the Paretian symptom reliability curve can be transformed to the average symptom life-curve of a given machine set.

TL;DR: In this article, a generic distributed parameter system is proposed and analyzed, where a generic layered shell made of a passive elastic material sandwiched between two piezoelectric layers is analyzed.

TL;DR: In this paper, a semi-active control strategy is developed to suppress vibration of flexible structures by on-line varying the characteristics of variable dampers, which is designed on the basis of sliding mode control theory.

TL;DR: In this article, the effect of hidden feedback paths on FRF estimators was investigated in a two-shaker sine-dwelling test on a circular disk, and the applicability of the closed-loop model was validated using results from experiments carried out on a circle disk.

TL;DR: In this paper, the authors summarise and suggest new extensions of three recently developed techniques for recovering harmonic signal information in the presence of additive unknown colored noise, which is important in many noise and vibration problems where it is desirable to distinguish truly periodic components from random narrowband components.

TL;DR: A diagnostic strategy is proposed on the basis of the method of state recognition and expert systems architecture and a new kind of distance function—quotient distance—is presented, which takes the sensitive feature as its major discriminating basis.

TL;DR: A non-linear analyser based on a multi-dimensional Fourier transform that allows drastic reduction of algebraic operations is presented and the Winograd fast algorithm is discussed.

TL;DR: In this article, a CAD compatible boundary element formulation is proposed for the prediction of mechanical mobility of a machine foundation, where the response of the entire structure is significantly influenced by the distributed restoring-, inertia-and damping-forces of these isolators.

TL;DR: In this article, an efficient method of identifying non-linear element positions and their type within a system or structure is suggested, allowing for the non-proportional relationship between input excitation force and resulting output responses, time domain excitation and response signals are used to detect the nonlinear elements positions.

TL;DR: In this article, a simple method to assess the safety of metallic structures in the presence of crack-like defects is considered, where linear regression techniques are used to fit fatigue-crack growth laws of exponential type with respect to the number of cycles, in FCG experimental results.

TL;DR: In this paper, a system for on-line detection of tool breakage in milling has been developed by using the difference of the quasi-mean resultant displacement of spindle.

TL;DR: The two-level identification procedure is developed and applied and, if the measurement errors of the component quantities are independent of each other, the quadratic objective function can be decomposed on the basis of these components.

TL;DR: In this paper, the authors used acoustic streamline functions and reciprocity techniques to predict the effect of inserting barriers in an acoustic cavity and which areas of the boundary are most sensitive to external input.

TL;DR: The equivalent beam stiffness (EBS) method as discussed by the authors is an extension to and improvement upon the technique of Thomas and Littlewood in which the effective stiffness diameter profile of a freely suspended rotor was estimated by applying the Euler-Bernoulli beam equation to the measured first lateral bending mode shape.

TL;DR: In this article, two new controller configurations for broad band adaptive noise control have been examined and compared with the ordinary transversal filter configuration in a computer simulation study and the results show that it is possible to obtain a significant reduction in the controller complexity if prior knowledge about the acoustic system is built into the controller.

TL;DR: In this article, the minimisation of the sum of the squares of the error signals over some defined time interval, using exact methods which give optimum time histories for the filter coefficients, is examined.

TL;DR: In this article, a set of user-friendly, computer programs for filter design and filtering are developed and implemented, and the viability of the non-recursive digital filters for the intended application is established with the use of acceleration signals obtained from a laboratory shock test.