An approach to reduce vibration and avoid shimmy on landing gears based on an adapted eigenstructure assignment theory

Laporte, Daniel; Lopes, Vicente; Bueno, Douglas Domingues

doi:10.1007/s11012-019-01101-4

Cited by 8 publications

(3 citation statements)

References 14 publications

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“…In addition, in recent years, both domestic and international scholars have conducted research on the control of shimmy, aiming to suppress it by installing controllers and selecting appropriate control strategies. Research results [24][25][26][27] have demonstrated that adopting suitable control strategies can effectively suppress the occurrence of shimmy. However, such studies have remained limited to the theoretical domain and have not been implemented in practice.…”

Section: Introductionmentioning

confidence: 97%

Effect of Multi-Joint Clearance Coupling on Shimmy of Nose Landing Gear

Feng,

Jiang,

Jiang

2023

Aerospace

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The existence of joint clearances in the nose landing gear (NLG) is inevitable and significantly affects shimmy. It was found that the interaction of each joint clearance is closely related to the analysis of shimmy stability. In this study, the shimmy model of NLG with three-dimensional joint clearance was established by using LMS VirtualLab Motion. Based on the method of multibody dynamics (MBD), the load transfer mechanism at the joints of the NLG was analyzed, and the oscillation characteristics with multiple joint clearances were investigated. The results indicate that the radial and axial contact force of the joint decreases from bottom to top, and the radial contact forces are relatively high at the end positions of the connection shafts, resulting in uneven wear. When the joint clearance reaches a certain value, periodic shimmy of the NLG will occur, and an increase in torsional damping can reduce the amplitude of the shimmy. Therefore, this study reveals the influence of multi-position joint clearance coupling on shimmy, and provides a valuable insight for the maintenance and design of landing gear joints.

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Section: Introductionmentioning

confidence: 97%

Effect of Multi-Joint Clearance Coupling on Shimmy of Nose Landing Gear

Feng,

Jiang,

Jiang

2023

Aerospace

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“…At present, there are no studies in the literature to distinguish and discuss it. Although many scholars have studied the shimmy suppression method of the NLG [31][32][33][34][35][36][37], it is impossible to establish the quantitative influence of joint clearance wear on NLG shimmy, which makes it difficult for the designer to analyze the reliability of the landing gear system, let alone accurately predict the joint life and monitor the motion state of the mechanism.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Joint Clearance Effects on the Shimmy of Nose Landing Gear

Jiang,

Feng,

Liu

et al. 2023

Aerospace

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Through the establishment of a three-dimensional joint clearance model, the effects of joint clearances at different positions on shimmy stability are evaluated. In this paper, considering the radial, axial and coupling characteristics of joint clearance, the shimmy multibody dynamics (MBD) model is applied to different joints in the nose landing gear (NLG) transmission system. It is proposed to evaluate the influence of joint clearance on shimmy from two aspects of position factor and wear factor. The study found that different joint clearances have different effects on shimmy: the joint clearance between the NLG and fuselage has little influence on shimmy; the larger axial clearance of upper and lower torque link joint will cause the shimmy of the NLG, but the radial clearance has no effect on shimmy; while the joint clearance between turning sleeve and upper torque link, lower torque link and piston only works in the axial and radial coupling. The reasons for the different influence characteristics of each joint space are analyzed. Consequently, studying and summarizing the influence of different clearance on shimmy is of great significance for the design and maintenance of the NLG joints.

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“…The results and robustness analysis of different test scenarios show that the proposed controller can suppress the shimmy more effectively than the PID controller. Laporte [6] studied the application of classical eat theory for calculating feedback control gain in aircraft landing gear shimmy. Taking the landing gear structural stiffness and damping increment as the gain matrix, the structural natural frequency and damping ratio are changed through the eigenvector and eigenvalue of the control matrix, so as to change the system characteristics to obtain a shimmy free system.…”

Section: Introductionmentioning

confidence: 99%

Amplitude reduction optimization of time delay semi-active control for aircraft landing gear shimmy

Zhao

2022

J. Phys.: Conf. Ser.

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Considering the time delay issue in the process of aircraft landing gear shimmy, the time delay semi-active control is used to achieve the purpose of amplitude reduction optimization. Firstly, in order to eliminate the influence of dimensionality and make the results better describe the objective universal law, after dimensionless treatment of the shimmy equations, the influence of dimensionless lateral bending damping coefficient and lateral bending stiffness coefficient of strut on the shimmy amplitude is analyzed. Then, in order to further reduce the amplitude, the time delay semi-active control term is introduced into the shimmy equations, and a mathematical method for solving the characteristic equation of the time-delay dynamic equation is proposed. Designing optimization criterion limits the amplitude of the first resonance to a small enough range. The time delay semi-active control can achieve good vibration reduction effect in the whole frequency domain and eliminate the second resonance. Finally, it is verified and compared in the frequency domain and time domain, the correctness of the calculation and the superiority of time delay semi-active control are proved.

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An approach to reduce vibration and avoid shimmy on landing gears based on an adapted eigenstructure assignment theory

Cited by 8 publications

References 14 publications

Effect of Multi-Joint Clearance Coupling on Shimmy of Nose Landing Gear

Effect of Multi-Joint Clearance Coupling on Shimmy of Nose Landing Gear

Evaluation of Joint Clearance Effects on the Shimmy of Nose Landing Gear

Amplitude reduction optimization of time delay semi-active control for aircraft landing gear shimmy

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