Nonlinear Dynamic Modelling of Two-Point and Symmetrically Supported Pipeline Brackets with Elastic-Porous Metal Rubber Damper

This paper aims to investigate the nonlinear dynamic properties of a two-point and symmetrically supported pipeline bracket system coated with the damping element using an elastic-porous metal rubber. The dynamic model of the studied two-point and symmetric pipeline system was established based on impulse response matrix for accurate and reliable description on its nonlinear behaviours, e.g., energy dissipation and loss factor. The experimental verification of the developed model was performed by means of dynamic test as well as the analyses of nonlinear damping characteristics. The experimental results show a good agreement with the prediction results obtained from the proposed dynamic model. This work provides an alternative method to investigate the dynamics of pipeline vibration system equipped with a damping structure.

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Damping Energy Dissipation and Parameter Identification of the Bellows Structure Covered with Elastic-Porous Metal Rubber

Shock and Vibration ◽

10.1155/2021/8813099 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Guojian Shen ◽

Min Li ◽

Xin Xue

Keyword(s):

Energy Dissipation ◽

Dynamic Model ◽

Constitutive Relation ◽

Dynamic Properties ◽

Porous Metal ◽

Generalized Least Squares ◽

Restoring Force ◽

Metal Rubber ◽

Vibration Parameters ◽

Nonlinear Constitutive Relation

In order to improve damping energy dissipation of a U-shaped bellows structure, elastic-porous metal rubber as a cover layer was adopted and the corresponding vibration parameters were identified. First, the evolution of energy dissipation characteristics with respect to the changes of amplitude and frequency was investigated through a dynamic experimental test in the bending direction of the covered bellows structure. Second, the conspicuous hysteresis loop characteristics were described while the nonlinear constitutive relation was analytically modelled based on the exact decomposition method. Third, the corresponding parameters on dynamic properties of the covered bellows structure were determined by generalized least-squares estimation. Finally, the prediction results were compared with the measured displacement-restoring force curves to verify the accuracy of the developed dynamic model. The results indicate that the proposed dynamic model associated with the nonlinear constitutive relation for the covered bellows structure can well describe the evolution of the restoring force in terms of amplitude and frequency.

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Thermo-mechanical behavior analysis of motorized spindle based on a coupled model

Advances in Mechanical Engineering ◽

10.1177/1687814017747144 ◽

2018 ◽

Vol 10 (1) ◽

pp. 168781401774714 ◽

Cited By ~ 3

Author(s):

Junfeng Liu ◽

Peng Zhang

Keyword(s):

Dynamic Model ◽

High Speed ◽

Dynamic Properties ◽

Dynamic Test ◽

Coupled Model ◽

Solution Procedure ◽

Motorized Spindle ◽

Proposed Model ◽

Motorized Spindles ◽

Rotor Dynamic

This article presents a thermo-mechanical coupled dynamic model for high-speed motorized spindles. The proposed model includes an angular ball bearing model, a thermal model, and a rotor dynamic model. The coupling relationship among these submodels is analyzed, and a solution procedure for the integrated model is designed. Based on the proposed model and solution procedure, the dynamic behaviors of the spindle system and the effects of the thermal displacement of the system on the behaviors are quantificationally discussed. Finally, an integrated dynamic test is carried out on a D62D24A-type motorized spindle, and the good agreement between the mathematical results and the experimental data indicates that the proposed model is capable of accurately predicting the dynamic properties of motorized spindles, and the accuracy of the model is improved when considering the thermo-mechanical coupled factor. The conclusions are useful for the dynamic design and the thermal compensation control of high-speed motorized spindles.

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Nonlinear Dynamic Modelling of Gear-Shaft-Disk-Bearing Systems Using Finite Elements and Describing Functions

Volume 4: 9th International Power Transmission and Gearing Conference, Parts A and B ◽

10.1115/detc2003/ptg-48848 ◽

2003 ◽

Author(s):

Rafiq Maliha ◽

Can U. Dog˘ruer ◽

H. Nevzat O¨zgu¨ven

Keyword(s):

Dynamic Model ◽

Nonlinear Dynamic ◽

Dynamic Modelling ◽

Spur Gear ◽

Discrete Models ◽

Nonlinear Dynamic Model ◽

Disk System ◽

Describing Functions ◽

Gear Mesh ◽

System A

This study presents a new nonlinear dynamic model for a gear-shaft-disk-bearing system. A nonlinear dynamic model of a spur gear pair is coupled with linear finite element models of shafts carrying them, and with discrete models of bearings and disks. The nonlinear elasticity term resulting from backlash is expressed by a describing function, and a method developed in previous studies to determine the harmonic responses of nonlinear multi degree of freedom systems is employed for the solution. The code developed, Nonlinear Geared Rotor Dynamics (NLGRD), combines the versatility of modeling a shaft-bearing-disk system that can have any configuration, with the accuracy of an advanced nonlinear gear mesh interface model. Thus any single stage gear mesh configuration can be modeled easily and accurately. NLGRD is capable of calculating dynamic gear loads, dynamic bearing forces, bearing displacements and making modal analysis of the corresponding linear system. Theoretical results obtained by NLGRD are compared with the experimental data available in literature.

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