Damage identification in vibrating rotor-shaft systems by efficient sampling approach

Szolc, Tomasz; Tauzowski, Piotr; Stocki, R.; Knabel, J.

doi:10.1016/j.ymssp.2008.12.007

Cited by 18 publications

(34 citation statements)

References 6 publications

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“…To avoid the abovementioned drawback and to maintain the obvious advantages of the finite element approach, in this paper, similarly as in [31][32][33][34], the dynamic analysis of the entire rotating system is performed by means of the one-dimensional hybrid structural model consisting of continuous visco-elastic macro-elements and discrete oscillators. Using such a model the rotor-shaft geometry as well as its material properties can be described in an identical way as in the analogous mentioned above finite element model of the same structure.…”

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

“…The complete mathematical formulation and solutions for such hybrid models of the rotor-shaft systems can be found e.g. in [31][32][33].…”

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

“…Similarly as in [31][32][33], mutual connections of the successive macro-elements creating the stepped shaft as well as their interactions with the supports and rigid bodies representing the heavy rotors are described by equations of boundary conditions. These equations contain geometrical conditions of conformity for translational and rotational displacements of extreme macroelement cross-sections.…”

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

“…Shaft interactions with discrete oscillators representing the shaft supports in journal bearings are also described by means of the dynamic boundary conditions. Here, similarly as in [32,33], such boundary conditions contain anti-symmetrical terms with cross-coupling oil-film stiffness components, which couple shaft bending vibrations in two mutually perpendicular planes. In these equations the stiffness and damping coefficients can be constant or variable, when non-linear properties of the oilfilm are taken into consideration.…”

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

“…The solution for the forced bending vibration analysis has been obtained using the analytical -computational approach demonstrated in detail in [31][32][33]. Solving the differential eigenvalue problem for the linearized orthogonal system and an application of the Fourier solutions in the form of series in orthogonal eigenfunctions leads to the set of modal equations in the Lagrange coordinates…”

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

See 4 more Smart Citations

Polynomial chaos expansion method in estimating probability distribution of rotor-shaft dynamic responses

Lasota¹,

Stocki²,

Tauzowski³

et al. 2015

Bulletin of the Polish Academy of Sciences Technical Sciences

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Abstract. The main purpose of the study is an assessment of computational efficiency of selected numerical methods for estimation of vibrational response statistics of a large multi-bearing turbo-generator rotor-shaft system. The effective estimation of the probability distribution of structural responses is essential for robust design optimization and reliability analysis of such systems. The analyzed scatter of responses is caused by random residual unbalances as well as random stiffness and damping parameters of the journal bearings. A proper representation of these uncertain parameters leads to multidimensional stochastic models. Three estimation techniques are compared: Monte Carlo sampling, Latin hypercube sampling and the sparse polynomial chaos expansion method. Based on the estimated values of the first four statistical moments the probability density function of the maximal vibration amplitude is evaluated by the maximal entropy principle method. The method is inherently suited for an accurate representation of the probability density functions with an exponential behavior, which appears to be characteristic for the investigated rotor-shaft responses. Performing multiple numerical tests for a range of sample sizes it was found that the sparse polynomial chaos method provides the best balance between the accuracy and computational effectiveness in estimating the unknown probability distribution of the maximal vibration amplitude.

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Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

“…The complete mathematical formulation and solutions for such hybrid models of the rotor-shaft systems can be found e.g. in [31][32][33].…”

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

Section: Polynomial Chaos Expansion Methods In Estimating Probability mentioning

confidence: 99%

See 3 more Smart Citations

Polynomial chaos expansion method in estimating probability distribution of rotor-shaft dynamic responses

Lasota¹,

Stocki²,

Tauzowski³

et al. 2015

Bulletin of the Polish Academy of Sciences Technical Sciences

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Semi‐active reduction of vibrations in the mechanical system driven by an electric motor

Michajłow

Jankowski

Szolc

et al. 2017

Optim Control Appl Methods

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Summary In this paper, a semi‐active damping approach is used for reduction of vibrations in a laboratory drivetrain system. The considered drivetrain system is powered by an electric, asynchronous motor at the one side and loaded with a harmonically varying torque on the other side. Here, an influence of electromechanical interaction, i.e., an electromechanical coupling, between the electric motor and the mechanical system has been taken into consideration. The harmonic load signal induces torsional vibrations in the system, which in the steady‐state phase of motion become periodic. The aim of the work is to determine the optimal control function for a semi‐active damping element, leading to vibration reduction and considering only the steady‐state phase of system motion. The optimal control is derived by using a semi‐analytical approach based on the optimal control theory aided with supplementary numerical computations. The proposed methodology is fully general, and it can be directly applied to any type of a periodically oscillating system.

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Model Based Identification of the Measured Vibration Multi-fault Diagnostic Signals Generated by a Large Rotating Machine

Szolc,

Konowrocki,

Pisarski

2023

Mechanisms and Machine Science

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Damage identification in vibrating rotor-shaft systems by efficient sampling approach

Cited by 18 publications

References 6 publications

Polynomial chaos expansion method in estimating probability distribution of rotor-shaft dynamic responses

Polynomial chaos expansion method in estimating probability distribution of rotor-shaft dynamic responses

Semi‐active reduction of vibrations in the mechanical system driven by an electric motor

Model Based Identification of the Measured Vibration Multi-fault Diagnostic Signals Generated by a Large Rotating Machine

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