Investigation of Rub-Impact Setup Supported on Flexible Multi-Bearing Rotor

2012 ◽  
Author(s):  
Abdulazim H. Falah ◽  
Emad A. Khorshid ◽  
Khalid A. Alhazza
Keyword(s):  
Nonlinear Dynamics ◽  
Mathematical Model ◽  
Ball Bearings ◽  
Vibration System ◽  
Test Rig ◽  
Chaotic Response ◽  
Impact Device ◽  
Modeling And Experiments ◽  
In The Beginning ◽  
The Mathematical Model

Vibration system investigation of the chaotic response of full annular rub impact rotor system supported on two ball bearings is investigated. Modeling and experiments of nonlinear dynamics on flexible multi-bearing rotor test rig is presented in this work. The test rig has two balancers that are assembled on rotor shaft, a rub impact device at the center, and ball bearings at both ends of the shaft. A 12-degree-of-freedom (DOF) linear model was developed for this test rig. The mathematical model was developed in the beginning without considering the rub impact part in order to validate the model with the experiment results. Then, then experimentally chaotic response and bifurcation diagram of the rub impact system were investigated.

scholarly journals Research on Chaos Response of the Nonlinear Vibration System of Giant Magnetostrictive Actuator

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Hongbo Yan ◽  
Yu Niu ◽  
Hong Gao ◽  
Hongbo Hao
Keyword(s):  
Mathematical Model ◽  
Amplitude Spectrum ◽  
Experimental Simulation ◽  
System Response ◽  
Threshold Condition ◽  
Vibration System ◽  
Chaotic Response ◽  
Magnetostrictive Actuator ◽  
Excitation Force ◽  
The Mathematical Model

In the present study, the chaotic response of the nonlinear magnetostrictive actuator (GMA) vibration system is investigated. The mathematical model of the nonlinear GMA vibration system is established according to J-A hysteresis nonlinear model, quadratic domain rotation model, Newton’s third law, and principle of GMA structural dynamics by analyzing the working principle of GMA. Then, the Melnikov function method is applied to the threshold condition of the chaotic response of the system to obtain the sense of Smale horseshoe transformation. Furthermore, the mathematical model is solved to investigate the system response to the excitation force and frequency. Accordingly, the corresponding displacement waveform, phase plane trajectory, Poincaré map, and amplitude spectrum are obtained. The experimental simulation is verified using Adams software. The obtained results show that the vibration equation of the nonlinear GMA vibration system has nonlinear and complex motion characteristics with different motion patterns. It is found that the vibration characteristics of the system can be controlled through adjusting the excitation force and frequency.

An Efficient Approach to Define the Input Stimuli to Suppress Epileptic Seizures Described by the Epileptor Model

2020 ◽  
Vol 30 (11) ◽  
pp. 2050062
Author(s):  
João Angelo Ferres Brogin ◽  
Jean Faber ◽  
Douglas Domingues Bueno
Keyword(s):  
Nonlinear Dynamics ◽  
Mathematical Model ◽  
Exact Solution ◽  
Feedback Control ◽  
Epileptic Seizures ◽  
Neural Dynamics ◽  
Practical Application ◽  
Control Gain ◽  
The World ◽  
The Mathematical Model

Epilepsy affects about 70 million people in the world. Every year, approximately 2.4 million people are diagnosed with epilepsy, two-thirds of them will not know the etiology of their disease, and 1% of these individuals will decease as a consequence of it. Due to the inherent complexity of predicting and explaining it, the mathematical model Epileptor was recently developed to reproduce seizure-like events, also providing insights to improve the understanding of the neural dynamics in the interictal and ictal periods, although the physics behind each parameter and variable of the model is not fully established in the literature. This paper introduces an approach to design a feedback-based controller for suppressing epileptic seizures described by Epileptor. Our work establishes how the nonlinear dynamics of this disorder can be written in terms of a combination of linear sub-models employing an exact solution. Additionally, we show how a feedback control gain can be computed to suppress seizures, as well as how specific shapes applied as input stimuli for this purpose can be obtained. The practical application of the approach is discussed and the results show that the proposed technique is promising for developing controllers in this field.

Rig Test and Analysis of Dynamic Engagement Process of Wet Clutch

2014 ◽  
Vol 945-949 ◽  
pp. 1461-1464
Author(s):  
Han Yu Jin ◽  
Xiu Sheng Cheng ◽  
Xiu Feng Song
Keyword(s):  
Mathematical Model ◽  
Experimental Verification ◽  
Constant Pressure ◽  
Simulation Analysis ◽  
Test Rig ◽  
Wet Clutch ◽  
Engagement Process ◽  
Working Principle ◽  
The Mathematical Model

The working principle of wet clutch was analyzed and the mathematical model was established for torque deliver. Experimental verification and simulation analysis was carried out for the clutch model in the situation of constant pressure engaging process. An efficiency examination of wet clutch implemented on the test rig and provided theory evidence for pressure precisely control.

Prediction of the Damaging Flow-Induced Vibrations in Tubular Heat Exchangers With Triangular Arrays

2014 ◽  
Author(s):  
Yehia A. Khulief ◽  
Salem A. Bashmal ◽  
Sayed A. Said ◽  
Dhawi A. Al-Otaibi ◽  
Khalid M. Mansour
Keyword(s):  
Mathematical Model ◽  
Service Life ◽  
Test Section ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Test Rig ◽  
Flow Rates ◽  
Tube Arrays ◽  
Flow Induced Vibrations ◽  
The Mathematical Model

The prediction of flow rates at which the vibration-induced instability takes place in tubular heat exchangers due to cross-flow is of major importance to the performance and service life of such equipment. In this paper, the semi-analytical model developed in [1] for square tube arrays was extended and utilized to study the triangular tube patterns. A laboratory test rig with instrumented test section is used to measure the fluidelastic coefficients to be used for tuning the mathematical model. The test section can be made of any bundle pattern. In this study, two test sections were constructed for both the normal triangular and the rotated triangular tube arrays. The developed scheme is utilized in predicting the onset of flow-induced instability in the two triangular tube arrays. The results are compared to those obtained for two other bundle configurations; namely the square and rotated square arrays reported in [1]. The results of the four different tube patterns are viewed in the light of TEMA predictions. The comparison demonstrated that TEMA guidelines are more conservative in all configurations considered.

scholarly journals ВИКОРИСТАННЯ МОДЕЛІ НЕЛІНІЙНОЇ ДИНАМІКИ ДЛЯ АНАЛІЗУ ВПЛИВУ СИСТЕМИ УПРАВЛІННЯ ЗНАННЯМИ НА РЕАЛІЗАЦІЮ ВИСОКОТЕХНОЛОГІЧНИХ ПРОЕКТІВ

2019 ◽  
pp. 76-82
Author(s):  
Василь Михайлович Вартанян ◽  
Дар'я Олександрівна Штейнбрехер
Keyword(s):  
Nonlinear Dynamics ◽  
Mathematical Model ◽  
Knowledge Management ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Management System ◽  
Knowledge Management System ◽  
Project Implementation ◽  
The Impact ◽  
The Mathematical Model

The article determines that at the present stage of the project management development in information-oriented society, the decision-making process on the efficiency of the knowledge management system assessment is complicated, due to the lack of approaches that determine the impact of the system on the project implementation. The article presents the main results of the analysis of the current state of the problem of modeling the knowledge management system of high-tech projects, which helped to establish that one of the factors of the introduction of an effective system of knowledge preservation is the ability to assess the impact of the system on the project environment.In order to solve the problem, the mathematical model of nonlinear dynamics for the analysis of the influence of knowledge management system on the project based on the Bulirsch–Stoer method was proposed, it is possible to evaluate the influence of elements of the knowledge management system on the projected stages of the project implementation and to calculate the duration of the project taking into account their influence. The mathematical model of nonlinear dynamics for the analysis of the influence of the knowledge management system on the Bulirsch–Stoer method is given to evaluate the influence of elements of the knowledge management system on the projected implementation stages and to calculate the duration of the project, taking into account their impact. Bulirsch–Stoer algorithm is a method for the numerical solution of ordinary differential equations which combines three powerful ideas: Richardson extrapolation, the use of rational function extrapolation in Richardson-type applications, and the modified midpoint method, to obtain numerical solutions to ordinary differential equations (ODEs) with high accuracy and comparatively little computational effort. The step-by-step tracking of the knowledge management system impact on the project development will allow the project manager to predict both its successful completion and the risks of deviation from the scheduled time due to the loss of critical knowledge, which largely stems from the successful implementation of the project.Further research will be aimed at developing a model that allows us to assess the profitability of the system in the design environment, based on the results of the proposed mathematical model.

Modeling and Experimental Validation of DNA Motion in Uniform and Nonuniform DC Electric Fields

2010 ◽  
Vol 1 (4) ◽  
Author(s):  
Regis A. David ◽  
Brian D. Jensen ◽  
Justin L. Black ◽  
Sandra H. Burnett ◽  
Larry L. Howell
Keyword(s):  
Mathematical Model ◽  
Electric Fields ◽  
New Technique ◽  
Strongly Correlated ◽  
System A ◽  
Modeling And Experiments ◽  
Foreign Dna ◽  
A New Technique ◽  
Dna Motion ◽  
The Mathematical Model

We are developing a new technique to insert foreign DNA into a living cell using a microelectromechanical system. This new technique relies on electrical forces to move DNA in a nonuniform electric field. To better understand this phenomenon, we perform integrated modeling and experiments of DNA electrophoresis. This paper describes the protocol and presents the results for DNA motion experiments using fabricated gel electrophoresis devices. We show that DNA motion is strongly correlated with ion transport (current flow) in the system. A better understanding of electrophoretic fundamentals allows for the creation of a mathematical model to predict the motion of DNA during electrophoresis in both uniform and nonuniform electric fields. The mathematical model is validated within 4% through comparison with the experimental results.

Fatigue Failure Progression in Ball Bearings

2000 ◽  
Vol 123 (2) ◽  
pp. 238-242 ◽  
Author(s):  
Michael N. Kotzalas ◽  
Tedric A. Harris
Keyword(s):  
Mathematical Model ◽  
Fatigue Life ◽  
Fatigue Failure ◽  
Heat Generation ◽  
Ring Test ◽  
Ball Bearings ◽  
Test Rig ◽  
Component Failure ◽  
Rolling Contacts ◽  
Total Failure

Typically, the life of a component containing rolling contacts is defined as the time to the initiation of a fatigue spall. Initiation of a spall does not always cause the component to stop performing its designed function. Operating the component past the initiation of a spall increases the heat generation rates and vibrations, eventually leading to total failure. A ball/v-ring test rig was used to initiate and progress spalls on bearing balls where spall progression was measured as a function of time, and vibrations monitored using accelerometers. A spall progression life mathematical model for balls endurance tested in the v-ring rig was created by extending the Ioannides–Harris fatigue life theory. Also, excessive vibratory loading was determined to be the major cause of total component failure.

scholarly journals Nonlinear Dynamics of Climate Model

2020 ◽  
Vol 12 (5) ◽  
pp. 73
Author(s):  
Sarah Saleh Saad Alassaf
Keyword(s):  
Nonlinear Dynamics ◽  
Mathematical Model ◽  
Land Surface ◽  
Climate Model ◽  
Surface Air Temperature ◽  
Neighborhood Characteristics ◽  
The Past ◽  
Hysteresis Controller ◽  
The Mathematical Model ◽  
Calculated Model

Incredible lack of meteorological information appears to be one of its principle highlights from the perspective of atmosphere elements estimations. The lack is caused by nonrenewable misfortunes in the past together with moderate assembling in the present. Along with these lines, here we talk about one of the path and how to utilize the accessible perceptions of land surface air temperature in request to get estimations on development of nearby atmosphere elements. Since such elements are described by too high assortment of nonlinear practices, at that point the bifurcation investigation remains the fundamental instrument to give sensible and unbiased results concerning evolutional forms. In this unique circumstance, we build up the way to deal with model-based reproduction of the elements based on supposed HDS-show (the model of a Hysteresis controller with Double Synchronization). At present, just this calculated model permits to depict the circumstances and end results relations between hysteresis wonders and also feed moves in a neighborhood space scale from the bifurcation examination perspective. We trust that the displayed dialog could help to focus on neighborhood characteristics of inescapable atmosphere changes, and, after, could evaluate fairly atmosphere and monetary impacts caused by such changes, particularly, in connection to a point of no arrival. In this article we will discuss how nonlinear dynamics of climate model. Since the mathematical model is very complex so we are solving it numerically and the model will be represented in a graphical way.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

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