A criterion for mode shape tracking: application to Campbell diagrams

Mogenier, Guillaume; Baranger, Thouraya; Ferraris, Guy; Dufour, Régis; Durantay, Lionel

doi:10.1177/1077546312463714

Cited by 10 publications

(6 citation statements)

References 18 publications

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“…The diagram is clearly observed thanks to solid curves obtained by the NC 2 O mode shape tracking method (see Section 3.3 and Ref. [34]). The unstable ranges of rotary speeds exist for some (F) modes from Ω = 280 rpm.…”

Section: D-wellmentioning

confidence: 93%

“…However, the mode shape associated with the k th eigenvalue at a speed of rotation may not correspond to the k th eigenvalue at the next speed, which makes difficult the continuous plot of the natural frequencies versus the speed of rotation.. This difficulty is overcomed by applying the NC 2 O mode shape tracking method [34].…”

Section: Classification and Mode Shape Trackingmentioning

confidence: 99%

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Campbell Diagram Computation for a Drillstring Immersed in Curved Wells

Nguyen

Tran

Andrianoely

et al. 2019

Journal of Vibration and Acoustics

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The drilling operations use a rotary slender structure introduced inside the drill well. The nonlinear dynamics with bit-bouncing, stick-slip phenomena, and pulsating mud flow may yield the premature wear and damage of drilling equipment and should be investigated to improve the reliability of drilling operations. This work presents the beam element formulation to model the drilling nonlinear dynamics. The well-pipe contacts are modeled by the radial elastic stops. The fluid–structure interactions are considered. The first step consists in computing the static position of structure to determine the contact points and calculate the preloaded state. These results are then considered to calculate the Campbell diagram. The potentially unstable speeds of rotation are identified. The results show that the modal coupling phenomena strongly occur for the three-dimensional well. The well-pipe contacts modify the modes in rotation, and the rotating fluid induces a strong deviation of the flexural mode curves.

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Section: D-wellmentioning

confidence: 93%

Section: Classification and Mode Shape Trackingmentioning

confidence: 99%

Campbell Diagram Computation for a Drillstring Immersed in Curved Wells

Nguyen

Tran

Andrianoely

et al. 2019

Journal of Vibration and Acoustics

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“…The Campbell diagram of the rotor test bench on a fixed base and without encoders is computed and presented in Figure 4. The tracking of the mode shapes is done by applying the NC 2 O criterion [35]. The solid, dashed and dash-dotted curves refer to the bending, axial and torsional modes, respectively.…”

Section: Presentation Of the On-board Rotor Test Benchmentioning

confidence: 99%

“…The same power spectral density (PSD) is built for the only two mono-axial accelerometers involved in the driving process of the 6-DOF shaker, with a theoretically nil cross-correlation between each other. This PSD is defined by two plateaus at 2.51 × 10 −4 g 2 /Hz in [20-31.6] Hz and [45-60] Hz and a third one at 2.51 × 10 −6 g 2 /Hz in [35][36][37][38][39][40] Hz. This specific profile permits avoiding the resonance of the axial mode and the first two bending modes (rows 1, 3 and 4 of Tab.…”

Section: Multi-axial Random Excitationmentioning

confidence: 99%

Dynamics of on-board rotors on finite-length journal bearings subject to multi-axial and multi-frequency excitations: numerical and experimental investigations

Briend

Châtelet

Dufour

et al. 2021

Mechanics & Industry

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On-board rotating machinery subject to multi-axial excitations is encountered in a wide variety of high-technology applications. Such excitations combined with mass unbalance forces play a considerable role in their integrity because they can cause parametric instability and rotor–stator interactions. Consequently, predicting the rotordynamics of such machines is crucial to avoid triggering undesirable phenomena or at least limiting their impacts. In this context, the present paper proposes an experimental validation of a numerical model of a rotor-shaft-hydrodynamic bearings system mounted on a moving base. The model is based on a finite element approach with Timoshenko beam elements having six degrees of freedom (DOF) per node to account for the bending, torsion and axial motions. Classical 2D rectangular finite elements are also employed to obtain the pressure field acting inside the hydrodynamic bearing. The finite element formulation is based on a variational inequality approach leading to the Reynolds boundary conditions. The experimental validation of the model is carried out with a rotor test rig, designed, built, instrumented and mounted on a 6-DOF hydraulic shaker. The rotor’s dynamic behavior in bending, torsion and axial motions is assessed with base motions consisting of mono- and multi-axial translations and rotations with harmonic, random and chirp sine profiles. The comparison of the predicted and measured results achieved in terms of shaft orbits, full spectrums, transient history responses and power spectral densities is very satisfactory, permitting the experimental validation of the model proposed.

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“…Internal material damping of the rotor shaft was included in the finite element model through two element Voigt model. Left and right modes of a laminated rotor supported on two fluid film bearings are utilized by Mogenier et al [27] to employ normalized cross complex orthogonality (nc 2 o) criterion for tracking the eigenvector associated to each eigenvalue close to veerings or crossings in the Campbell diagram. Most of the researcher implemented this technique for the conventional second order system.…”

mentioning

confidence: 99%