scholarly journals Time-Domain Dynamic Modeling and Analysis of Complex Heavy-Duty Gearbox Considering Floating Effect

2021 ◽  
Vol 11 (15) ◽  
pp. 6876
Author(s):  
Jiulin Wu ◽  
Yifan Zhou ◽  
Wei Jiang ◽  
Xuedong Chen
Keyword(s):  
Dynamic Behavior ◽  
Time Domain ◽  
Planetary Gear ◽  
Modeling Method ◽  
Torsional Stiffness ◽  
Heavy Duty ◽  
Wind Turbine Gearbox ◽  
Modeling And Analysis ◽  
Meshing Gears ◽  
The Time Domain

Expert insights into the time-domain dynamic behavior of heavy-duty gearboxes form the foundations of design evaluation and improvement. However, in the existing lateral–torsional coupling (LTC) modeling method for gearboxes that is normally used for frequency-domain dynamic behavior, the meshing forces are modeled as spring dampers with fixed acting points on the meshing gears to simulate only the transient LTC effect, and thus the steady state characteristic in the time domain cannot be obtained due to the unrealistic distortion of positions and orientations as the gear angles increase. In this paper, a novel and generally applicable LTC modeling method for heavy-duty gearboxes, mainly planetary gear sets with floating components, is proposed by using space-fixed spring dampers with floating acting points on the meshing gears to study the time-domain dynamic response and to support the dynamic design of heavy-duty gearboxes. Based on the proposed method, a LTC model of a 2 megawatt (MW) wind turbine gearbox with floating components considering the time-varying meshing stiffness, bearing stiffness, torsional stiffness, and floating effect was established. The simulated results of representative components were in accordance with experimental results on a test rig, and dynamic behavior was calculated.

Fault features analysis of a compound planetary gear set with damaged planet gears

2017 ◽  
Vol 232 (9) ◽  
pp. 1586-1604 ◽  
Author(s):  
Guoyan Li ◽  
Fangyi Li ◽  
Haohua Liu ◽  
Dehao Dong
Keyword(s):  
Time Domain ◽  
Planetary Gear ◽  
Significant Feature ◽  
Time Interval ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Vibration Signals ◽  
Fault Features ◽  
Fault Properties ◽  
The Time Domain

The fault properties of compound planetary gear set are much more complicated than the simple planetary gear set. A damaged planet will induce two periodic transient impulses in the raw signals and generates modulation sidebands around the mesh harmonics. This paper aims to investigate the fault properties of a compound planetary gear set in damaged planet conditions. A dynamic model is proposed to simulate the vibration signals. The time interval between the fault-induced close impulses in the time domain is used as a significant feature to locate the faulty planet. Considering the phase relations, the time-varying mesh stiffness is obtained. Then, the fault properties are demonstrated in the simulation, and the theoretical derivations are experimentally verified.

Q-compensated reverse time migration in tilted transversely isotropic media

Geophysics ◽  
2020 ◽  
pp. 1-79
Author(s):  
Ali Fathalian ◽  
Daniel O. Trad ◽  
Kristopher A. Innanen
Keyword(s):  
Time Domain ◽  
Transversely Isotropic ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Modeling And Analysis ◽  
Seismic Amplitude ◽  
Time Migration ◽  
Transversely Isotropic Media ◽  
Isotropic Media ◽  
The Time Domain

Anisotropy and absorption are critical to the modeling and analysis of seismic amplitude,phase, and traveltime data. To neglect any of these phenomena, which are often bothoperating simultaneously, degrades the resolution and interpretability of migrated images.However, a full accounting of anisotropy and anelasticity is computationally complex andexpensive. One strategy for accommodating these aspects of wave propagation, while keepingcost and complexity under control, is to do so within an acoustic approximation. Weset up a procedure for solving the time-domain viscoacoustic wave equation for tilted transverselyisotropic (TTI) media, based on a standard linear solid model and, from this, developa viscoacoustic reverse time migration (Q-RTM) algorithm. In this approach, amplitudecompensation occurs within the migration process through a manipulation of attenuationand phase dispersion terms in the time domain differential equations. Specifically, theback-propagation operator is constructed by reversing the sign only of the amplitude lossoperators, but not the dispersion-related operators, a step made possible by reformulatingthe absorptive TTI equations such that the loss and dispersion operators appear separately.The scheme is tested on synthetic examples to examine the capacity of viscoacoustic RTM to correct for attenuation, and the overall stability of the procedure.

scholarly journals Normalized Study of Three-Parameter System in the Time Domain and Frequency Domain

2017 ◽  
Vol 2017 ◽  
pp. 1-21
Author(s):  
Xiao-Lei Jiao ◽  
Yang Zhao ◽  
Wen-Lai Ma
Keyword(s):  
Frequency Domain ◽  
Dynamic Behavior ◽  
Time Domain ◽  
Phase Margin ◽  
Stiffness Ratio ◽  
Parameter System ◽  
Regulatory Factor ◽  
First Case ◽  
The Time Domain ◽  
Isolation Performance

Three-parameter isolation system can be used to isolate microvibration for control moment gyroscopes. Normalized analytical model for three-parameter system in the time domain and frequency domain is proposed by using analytical method. Dynamic behavior of three-parameter system in the time domain and frequency domain is studied. Response in the time domain under different types of excitations is analyzed. In this paper, a regulatory factor is defined in order to analyze dynamic behavior in the frequency domain. For harmonic excitation, a comparison study is made on isolation performance between the case when the system has optimal damping and the case when regulatory factor is 1. Besides, phase margin of three-parameter system is obtained. Results show that dynamic behavior in the time domain and frequency domain changes with regulatory factor. Phase margin has the largest value when the value of regulatory factor is 1. System under impulse excitation and step excitation has the shortest settling time for the response in the time domain when the value of regulatory factor is 1. When stiffness ratio is small, isolation performances of two cases are nearly the same; when system has a large stiffness ratio, isolation performance of the first case is better.

Finite Element Modelling of Rotating Tires in the Time Domain

2002 ◽  
Vol 30 (1) ◽  
pp. 19-33 ◽  
Author(s):  
O. A. Olatunbosun ◽  
A. M. Burke
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Time Domain ◽  
Equations Of Motion ◽  
Operating Conditions ◽  
Element Analysis ◽  
Successful Model ◽  
Linear Effects ◽  
Tire Rotation ◽  
The Time Domain

Abstract Finite element analysis presents an opportunity for a detailed study of the dynamic behavior of a rotating tire under real operating conditions providing a better understanding of the influence of tire construction and material detail on tire dynamic behavior in such areas as ride, handling and noise and vibration transmission. Modelling issues that need to be considered include non-linear effects due to tire inflation and hub loading, tire/road contact and time domain solution of the equations of motion. In this paper techniques and strategies for tire rotation modelling are presented and discussed as a guide to the creation of a successful model.

Vibration Test and Fault Diagnosis for Main Hoist Gearbox of Heavy Casting Crane

2014 ◽  
Vol 532 ◽  
pp. 374-377
Author(s):  
Zhang Li ◽  
Xing Dong Wang ◽  
Chang Yi Hu ◽  
Chi Zhong Chen ◽  
Li Ming
Keyword(s):  
Fault Diagnosis ◽  
Time Domain ◽  
Planetary Gear ◽  
Vibration Signal ◽  
Vibration Test ◽  
Signal Characteristic ◽  
Engineering Software ◽  
Fault Type ◽  
The Time Domain ◽  
Main Hoist

In view of the structure and running characteristics of gearbox of large and special crane, we have respectively carried out vibration test of fault and free-fault gearbox containing planetary gear in the work. With the help of Matlab engineering software, we can read and process the collected vibration signal of gearbox and draw the time-domain and frequency-domain graph. Through the comparative analysis of vibration information of gearboxes, we can determine the link between fault type and signal characteristic value, effectively realize the fault diagnosis of gearbox.

Modeling and Transient Response of Cable Network

2012 ◽  
Vol 433-440 ◽  
pp. 2868-2873
Author(s):  
Xing Zhou ◽  
Zhen Yu Xiang ◽  
Er Wei Cheng ◽  
Li Si Fan
Keyword(s):  
Transmission Line ◽  
Time Domain ◽  
Modeling Method ◽  
Domain Model ◽  
Domain Modeling ◽  
Cable Network ◽  
Cable Networks ◽  
Time Domain Modeling ◽  
The Time Domain ◽  
Line Network

This paper introduces modeling method for calculating nodes responses of transmission-line network directly in the time domain. Arising from classical telegrapher equations, the time-domain model of transmission line is gained. The transmission-line model, together with transmission-line nodes model, form the network model. Using the time-domain modeling method, transient responses for two given networks are gained. The injection experiments to cable networks are done to validate the calculating results. The consistency of calculating results with measure results indicates the model is feasible.

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