Self-excited oscillations attenuation of drill-string system using nonlinear energy sink

2012 ◽  
Vol 227 (2) ◽  
pp. 230-245 ◽  
Author(s):  
Z Nili Ahmadabadi ◽  
SE Khadem
Keyword(s):  
Steady State ◽  
Nonlinear Energy Sink ◽  
Drill String ◽  
Vibration Model ◽  
Steady State Responses ◽  
Stable Equilibria ◽  
Energy Sink ◽  
Parameter Values ◽  
State Responses ◽  
Nonlinear Energy

Application of nonlinear energy sink in annihilating self-excited oscillations of a slightly modified experimental and theoretical torsional vibration model of drill-string with real parameter values is studied in this article. Various configurations have been examined in order to procure steady-state responses in less time and expand the range of the existence of stable equilibria. Moreover, applied modification to the experimental model resulted in more realistic response. It is proven that attaching nonlinear energy sink to different components of a drill-string would help to acquire better responses and/or to improve applicability of the nonlinear energy sink.

scholarly journals Dynamics of Nonlinear Primary Oscillator with Nonlinear Energy Sink under Harmonic Excitation: Effects of Nonlinear Stiffness

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Min Sun ◽  
Jianen Chen
Keyword(s):  
Averaging Method ◽  
Nonlinear Energy Sink ◽  
Excitation Amplitude ◽  
Harmonic Excitation ◽  
Nonlinear Stiffness ◽  
Frequency Range ◽  
Steady State Responses ◽  
Energy Sink ◽  
State Responses ◽  
Nonlinear Energy

The dynamics of a system consisting of a nonlinear primary oscillator, subjected to a harmonic external force, and a nonlinear energy sink (NES) are investigated. The analytical solutions for the steady-state responses are obtained by the complexification-averaging method and the analytical model is confirmed by numerical simulations. The results indicate that the introduction of the NES can effectively suppress the vibrations of the primary oscillator. However, as the excitation amplitude increased, the NES may lose its efficiency within certain frequency range due to the appearance of the high response branches. Following the results analysis, it is concluded that this failure can be eliminated by reducing the nonlinear stiffness of the NES properly. The effects of nonlinear stiffness of the primary oscillator on the corresponding responses are also studied. The increase in this nonlinear stiffness can reduce the response amplitude and alter the frequency band where the high branches exist.

scholarly journals Dynamics of Cubic and Vibro-Impact Nonlinear Energy Sink: Analytical, Numerical, and Experimental Analysis

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Tao Li ◽  
Sébastien Seguy ◽  
Alain Berlioz
Keyword(s):  
Steady State ◽  
Invariant Manifold ◽  
General Equation ◽  
Analytical Procedure ◽  
Multiple Scales ◽  
Nonlinear Energy Sink ◽  
Periodic Forcing ◽  
State Response ◽  
Energy Sink ◽  
Nonlinear Energy

This paper is devoted to study and compare dynamics of primary linear oscillator (LO) coupled to cubic and vibro-impact (VI) nonlinear energy sink (NES) under transient and periodic forcing. The classic analytical procedure combining the approach of invariant manifold and multiple scales is extended from the analysis of steady-state resonance to other regimes, especially strongly modulated response (SMR). A general equation governing the variation of motion along the slow invariant manifold (SIM) is obtained. Numerical results show its convenience to explain the transition from steady-state response to SMR and the characteristics of SMR for periodic forcing. Targeted energy transfer (TET) under transient forcing can also be well understood. Experimental results from LO coupled to VI NES under periodic forcing confirm the existence of SMR and its properties (e.g., chaotic). They also verify the feasibility of the general equation to explain complicated case like SMR in experiments.

scholarly journals Passive Suppression of Panel Flutter Using a Nonlinear Energy Sink

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jian Zhou ◽  
Minglong Xu ◽  
Wei Xia
Keyword(s):  
Dynamic Pressure ◽  
Nonlinear Energy Sink ◽  
Aerodynamic Load ◽  
Panel Flutter ◽  
Aeroelastic Model ◽  
Suitable Combination ◽  
Energy Sink ◽  
The Galerkin Method ◽  
Parameter Values ◽  
Nonlinear Energy

A nonlinear energy sink (NES) is used to suppress panel flutter. A nonlinear aeroelastic model for a two-dimensional flat panel with an NES in supersonic flow is established using the Galerkin method. First-order piston aerodynamic theory is adopted to build the aerodynamic load. The effects of NES parameters on flutter boundaries of the panel are investigated using Lyapunov’s indirect method. The mechanism of the NES suppression of panel flutter is studied through energy analysis. Effects of NES parameters on aeroelastic responses of the panel are obtained, and a design technique is adopted to find a suitable combination of parameter values of the NES that suppresses the panel flutter effectively. Results show that the NES can increase or reduce the onset dynamic pressure of the panel flutter and it can reduce the aeroelastic response amplitude effectively within a certain range of dynamic pressure behind the onset dynamic pressure. The installation position of the NES depends on the direction of the airflow. The robust characteristics should be considered to find the suitable combination of parameter values of the NES.

Complexification-Averaging Analysis on a Giant Magnetostrictive Harvester Integrated With a Nonlinear Energy Sink

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Zhi-Wei Fang ◽  
Ye-Wei Zhang ◽  
Xiang Li ◽  
Hu Ding ◽  
Li-Qun Chen
Keyword(s):  
Steady State ◽  
Energy Harvester ◽  
Nonlinear Energy Sink ◽  
Analytical Approximation ◽  
Differential Algebraic Equations ◽  
Primary System ◽  
Algebraic Equations ◽  
Giant Magnetostrictive Material ◽  
Energy Sink ◽  
Nonlinear Energy

The present study aims to investigate the steady-state response regimes of a device comprising a nonlinear energy sink (NES) and a giant magnetostrictive energy harvester utilizing analytical approximation. The complexification-averaging (CX-A) technique is generalized to systems defined by differential algebraic equations (DAEs). The amplitude-frequency responses are compared with numerical simulations for validation purposes. The tensile and compressive stresses of giant magnetostrictive material (GMM) are checked to ensure that the material functions properly. The energy harvested is calculated and the comparison of transmissibility of the apparatus with and without NES–GMM is exhibited to reveal the performance of vibration mitigation. Then, the stability and bifurcations are examined. The outcome demonstrates that the steady-state periodic solutions of the system undergo saddle-node (SN) bifurcation at a certain set of parameters. In the meantime, no Hopf bifurcation is observed. The introduction of NES and GMM for vibration reduction and energy harvesting brings about geometric nonlinearity and material nonlinearity. By computing both the responses of the primary system equipped with the NES only and the NES–GMM, it is indicated that the added GMM can dramatically modify the steady-state dynamics. A further optimization with respect to the cubic stiffness, the damper of NES, and the amplitude of excitation is conducted, respectively. The boundary where the giant magnetostrictive energy harvester is out of work is pointed out as well during the process of optimizing.

Design Procedure of a Nonlinear Vibration Absorber Using Bifurcation Analysis: Application to the Drill-String System

2009 ◽  
Author(s):  
Re´gis Viguie´ ◽  
Gae¨tan Kerschen
Keyword(s):  
Design Procedure ◽  
Nonlinear Energy Sink ◽  
Drill String ◽  
Vibration Absorber ◽  
Nonlinear Structures ◽  
Targeted Energy Transfer ◽  
Vibration Level ◽  
Analysis Application ◽  
Energy Sink ◽  
Nonlinear Energy

A nonlinear energy sink (NES) is characterized by its ability to passively realize targeted energy transfer as well as multimodal damping. This latter feature seems to make this device very well suited for reducing the vibration level of MDOF linear and nonlinear structures. The perspective of dealing with such primary structures requires the development of an efficient NES design procedure. This paper poses the basis of such a procedure that is applied to the vibration mitigation of a drill-string system, using the software MatCont.

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