scholarly journals Dynamic Modeling of a Front-Loading Type Washing Machine and Model Reliability Investigation

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 289
Author(s):  
Jungjoon Park ◽  
Sinwoo Jeong ◽  
Honghee Yoo
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Equations Of Motion ◽  
Rigid Bodies ◽  
Washing Machine ◽  
System Parameters ◽  
Linear Dynamic ◽  
Revolute Joints ◽  
Model Reliability ◽  
Loading Type

A linear dynamic model of a front-loading type washing machine was developed in this study. The machine was conceptualized with three moving rigid bodies, revolute joints, springs, and dampers along with prescribed rotational drum motion. Kane’s method was employed for deriving the equations of motion of the idealized washing machine. Since the modal and transient characteristics can be conveniently investigated with a linear dynamic model, the linear model can be effectively used for the design of an FL type washing machine. Despite the convenience, however, the reliability of the linear dynamic model is often restricted to a certain range of system parameters. Parameters relevant to the reliability of the linear dynamic model were identified and the parameters’ ranges that could guarantee the reliability of the proposed linear dynamic model were numerically investigated in this study.

Dynamic modeling and simulation of two cooperating structurally-flexible robotic manipulators

Robotica ◽  
1995 ◽  
Vol 13 (4) ◽  
pp. 375-384 ◽  
Author(s):  
K. Krishnamurthy ◽  
L. Yang
Keyword(s):  
Modeling And Simulation ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Equations Of Motion ◽  
Robotic Manipulators ◽  
Geometric Constraints ◽  
Flexible Manipulators ◽  
Order Model ◽  
Closed Chain ◽  
Extended Hamilton’S Principle

SummaryA dynamic model for two three-link cooperating structurally-flexible robotic manipulators is presented in this study. The equations of motion are derived using the extended Hamilton's principle and Galerkin's method, and must satisfy certain geometric constraints due to the closed chain formed by the two manipulators and the object. The dynamic model presented here is for the purpose of designing controllers. Therefore, a low-order model which captures all the major effects is of interest. Computer simulated results are presented for the case of moving an object along an elliptical path using the two cooperating flexible manipulators.

scholarly journals Dynamic model of multi-rigid-body systems based on particle dynamics with recursive approach

2005 ◽  
Vol 2005 (4) ◽  
pp. 365-382 ◽  
Author(s):  
Hazem Ali Attia
Keyword(s):  
Rigid Body ◽  
Dynamic Model ◽  
Equations Of Motion ◽  
Particle Dynamics ◽  
Rigid Bodies ◽  
Constrained System ◽  
Open Chain ◽  
Chain System ◽  
Closed Chain ◽  
Serial Chains

A dynamic model for multi-rigid-body systems which consists of interconnected rigid bodies based on particle dynamics and a recursive approach is presented. The method uses the concepts of linear and angular momentums to generate the rigid body equations of motion in terms of the Cartesian coordinates of a dynamically equivalent constrained system of particles, without introducing any rotational coordinates and the corresponding rotational transformation matrix. For the open-chain system, the equations of motion are generated recursively along the serial chains. A closed-chain system is transformed to open-chain by cutting suitable kinematical joints and introducing cut-joint constraints. An example is chosen to demonstrate the generality and simplicity of the developed formulation.

Dynamic Modeling of Serial Manipulator Arms

1982 ◽  
Vol 104 (3) ◽  
pp. 218-228 ◽  
Author(s):  
M. Thomas ◽  
D. Tesar
Keyword(s):  
Dynamic Modeling ◽  
Simple Form ◽  
Dynamic Properties ◽  
Equations Of Motion ◽  
Model Formulation ◽  
Serial Manipulators ◽  
System Parameters ◽  
Industrial Manipulator ◽  
Influence Coefficients ◽  
Link Model

To design and precisely control a manipulator requires a representative dynamic model of the system. This paper presents the derivation of a rigid-link model for the serial manipulator, which reduces all of the arm’s dynamic properties to their effective values at the generalized inputs. The component terms of the model are readily calculated from the dynamic influence coefficients, which are based only on the geometry of the system. All necessary influence coefficients for serial manipulators are given in a particularly simple form. The model formulation keeps the system parameters and the input dynamics explicit in the controlling equations of motion, such that analysis and dynamic response results can be obtained in the most direct manner. Dynamic analysis results for an industrial manipulator are presented.

Dynamic Modeling of Underway Ship-to-Ship Operations

2011 ◽  
Author(s):  
Carlos Eduardo Silva de Souza ◽  
Helio Mitio Morishita
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Hydrodynamic Interaction ◽  
Equations Of Motion ◽  
Wave Interaction ◽  
Memory Effects ◽  
The Other ◽  
Transfer Phase ◽  
Mooring Lines

A dynamic model for underway ship-to-ship operations with surge velocity is developed. It is admitted that one ship develops power ahead, towing the other vessel together. Models for all relevant loads involved in such operation are present, like environment, mooring, fenders and hydrodynamic interaction loads. The equations of motion take fluid memory effects and wave interaction into account. The model was implemented and simulations were carried out, focusing in the transfer phase of a STS operation. The results are used to analyze mooring lines loads, which is a useful tool for mooring schemes design.

scholarly journals Planetary Gearbox Dynamic Modeling Considering Bearing Clearance and Sun Gear Tooth Crack

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2638
Author(s):  
Xianhua Chen ◽  
Xingkai Yang ◽  
Ming J. Zuo ◽  
Zhigang Tian
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Failure Modes ◽  
Gear Tooth ◽  
Working Environment ◽  
The Sun ◽  
Planetary Gearbox ◽  
Bearing Clearance ◽  
Vibration Responses ◽  
Planet Gear

Planetary gearbox systems are critical mechanical components in heavy machinery such as wind turbines. They may suffer from various failure modes, due to the harsh working environment. Dynamic modeling is a useful method to support early fault detection for enhancing reliability and reducing maintenance costs. However, reported studies have not considered the sun gear tooth crack and bearing clearance simultaneously to analyze their combined effect on vibration characteristics of planetary gearboxes. In this paper, a dynamic model is developed for planetary gearboxes considering the clearance of planet gear, sun gear, and carrier bearings, as well as sun gear tooth crack levels. Bearing forces are calculated considering bearing clearance, and the dynamic model equations are updated accordingly. The results reveal that the combination of bearing clearances can affect the vibration response with sun gear tooth crack by increasing the kurtosis. It is found that the effect of planet gear bearing clearance is very small, while the sun gear and carrier bearing clearance has clear impact on the vibration responses. These findings suggest that the incorporation of bearing clearance is important for planetary gearbox dynamic modeling.

Spring-Arrangement Effect on Flow-Induced Vibration of a Circular Cylinder

2021 ◽  
Author(s):  
Koki Yamada ◽  
Yuga Shigeyoshi ◽  
Shuangjing Chen ◽  
Yoshiki Nishi
Keyword(s):  
Circular Cylinder ◽  
Dynamic Model ◽  
Geometric Nonlinearity ◽  
Water Channel ◽  
Fluid Flows ◽  
Flow Induced Vibration ◽  
Theoretical Evaluation ◽  
Circulating Water ◽  
Linear Dynamic ◽  
Elastically Supported

Abstract Purpose This study elucidated the effect of an inclined spring arrangement on the flow-induced vibration of a circular cylinder to understand if the effect enhances the harnessing of the energy of fluid flows. Method An experiment was conducted on a circulating water channel. A circular cylinder was partially submerged. It was elastically supported by two springs whose longitudinal directions were varied. With the speed of the water flow varied, the vibrations of the circular cylinder were measured. The measured vibrations were interpreted by la linear dynamic model. Results and discussion In a few cases, a jump in response amplitudes from zero to the maximum was observed with the spring inclination at reduced velocities of 6 to 7, whereas gradually increasing response amplitudes were observed in other cases. The inclined spring arrangement achieved greater velocity amplitudes than in cases without spring inclination. A theoretical evaluation of the measured responses indicates that the effect of the inclined springs was caused by geometric nonlinearity; the effect would be more prominent by employing a longer moment lever.

Effect of Material and Geometric Parameters on the Steady-State Belt Stresses and Belt Slip for Flat Belt-Drives

2015 ◽  
Author(s):  
Cagkan Yildiz ◽  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Steady State ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Flexible Multibody Dynamics ◽  
Friction Model ◽  
Rigid Bodies ◽  
Geometric Parameters ◽  
Rubber Matrix ◽  
Axial Stiffness ◽  
Belt Drive

In order to accurately predict the fatigue life and wear life of a belt, the various stresses that the belt is subjected to and the belt slip over the pulleys must be accurately calculated. In this paper, the effect of material and geometric parameters on the steady-state stresses (including normal, tangential and axial stresses), average belt slip for a flat belt, and belt-drive energy efficiency is studied using a high-fidelity flexible multibody dynamics model of the belt-drive. The belt’s rubber matrix is modeled using three-dimensional brick elements and the belt’s reinforcements are modeled using one dimensional truss elements. Friction between the belt and the pulleys is modeled using an asperity-based Coulomb friction model. The pulleys are modeled as cylindrical rigid bodies. The equations of motion are integrated using a time-accurate explicit solution procedure. The material parameters studied are the belt-pulley friction coefficient and the belt axial stiffness and damping. The geometric parameters studied are the belt thickness and the pulleys’ centers distance.

Sensor Dynamic Modeling Based on LS-SVM and NGA

2008 ◽  
Vol 381-382 ◽  
pp. 439-442
Author(s):  
Qi Wang ◽  
Zhi Gang Feng ◽  
K. Shida
Keyword(s):  
Genetic Algorithm ◽  
Neural Networks ◽  
Support Vector Machine ◽  
Least Squares ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Support Vector ◽  
Local Minima ◽  
Highly Nonlinear ◽  
Sharing Function

Least squares support vector machine (LS-SVM) combined with niche genetic algorithm (NGA) are proposed for nonlinear sensor dynamic modeling. Compared with neural networks, the LS-SVM can overcome the shortcomings of local minima and over fitting, and has higher generalization performance. The sharing function based niche genetic algorithm is used to select the LS-SVM parameters automatically. The effectiveness and reliability of this method are demonstrated in two examples. The results show that this approach can escape from the blindness of man-made choice of LS-SVM parameters. It is still effective even if the sensor dynamic model is highly nonlinear.

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