Dynamic Behavior of Time-Domain Features for Prosthesis Control

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.

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Finite Element Modelling of Rotating Tires in the Time Domain

Tire Science and Technology ◽

10.2346/1.2135244 ◽

2002 ◽

Vol 30 (1) ◽

pp. 19-33 ◽

Cited By ~ 10

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.

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

Applied Sciences ◽

10.3390/app11156876 ◽

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.

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Dynamic Behavior of a Seawater Intake Riser

Volume 5B: Pipelines, Risers, and Subsea Systems ◽

10.1115/omae2017-62109 ◽

2017 ◽

Author(s):

Patrícia Mika Sakugawa ◽

Celso Kazuyuki Morooka

Keyword(s):

Dynamic Behavior ◽

Time Domain ◽

Time Integration ◽

Vertical Motion ◽

Computational Method ◽

Coupled Analysis ◽

Environmental Loads ◽

Newton Raphson ◽

Heave Motion ◽

Raphson Method

The main purpose of this work is to study a two dimensional coupled analysis, in vertical and lateral directions, of the dynamic behavior of a seawater intake riser (SWIR). The dynamic solution is performed in time domain, through the time integration Newmark-beta method, and the use of the Newton Raphson method to solve the nonlinearity problem. A finite element computational method is deployed to have a better understanding of the vertical motion contribution in the overall system, taking into account the environmental loads (wave) and the heave motion of the FLNG vessel.

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Dynamic behavior of pipelines and risers due to vortex-induced vibration in time domain

Marine Systems & Ocean Technology ◽

10.1007/bf03449253 ◽

2011 ◽

Vol 6 (1) ◽

pp. 17-26 ◽

Cited By ~ 5

Author(s):

Celso K. Morooka ◽

Raphael I. Tsukada

Keyword(s):

Dynamic Behavior ◽

Time Domain ◽

Vortex Induced Vibration

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Experimental Investigation on the Lumped Model of Nonlinear Rocker–Rocker Mechanism With Flexible Coupler

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4046157 ◽

2020 ◽

Vol 142 (6) ◽

Author(s):

Ren-Jung Chang ◽

Ying-Chuan Wang

Keyword(s):

Dynamic Behavior ◽

Time Domain ◽

Linear Time ◽

Harmonic Balance Method ◽

Model Averaging ◽

Lumped Model ◽

Linear Time Invariant ◽

Domain Identification ◽

Flexible Mechanism ◽

The Time Domain

Abstract The nonlinear and flexible effects on the continuum dynamics of rocker–rocker flexible mechanism are investigated. An experimental rocker–rocker mechanism with flexible coupler was first established. The flexible mechanism which incorporats the buckling motion of flexible coupler is acted as a double-well oscillator. The mechanism was actuated by electromagnet and measured by charge-coupled device (CCD) visual system. Rich dynamic behavior such as complex period, amplitude modulation, and chaos in the intrawell and interwell oscillations were observed. For investigating nonlinear dynamics, the dynamic behavior was analyzed through identification of linear and nonlinear lumped models. Both time-domain and frequency-domain approaches were carried out in identifying linear time-invariant model. Averaging multiple models were employed for the time-domain identification of linear model. The identification of nonlinear model was undertaken by the extension of the two-stage linear identification scheme. The response identification in input space was analyzed by utilizing semi-analytical harmonic balance method. The important boundary of chaotic response in operation was investigated by the proposed energy-well criterion, Melnikov's criterion, Moon's criterion, as well as Szemplińska-Stupnicka and Rudowski's criterion.

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