Nonlinear Characteristics of Universal Mathematical Model of Mesoscale Eddy

2021 ◽  
pp. 171-177
Author(s):  
Shu-Tang Liu ◽  
Yu-Pin Wang ◽  
Zhi-Min Bi ◽  
Yin Wang
Keyword(s):  
Mathematical Model ◽  
Mesoscale Eddy ◽  
Nonlinear Characteristics

Discrete Preisach Model of a Shape Memory Alloy Actuator

2016 ◽  
Vol 248 ◽  
pp. 227-234
Author(s):  
Waldemar Rączka ◽  
Jarosław Konieczny ◽  
Marek Sibielak ◽  
Janusz Kowal
Keyword(s):  
Mathematical Model ◽  
Shape Memory Alloy ◽  
Parameter Identification ◽  
Shape Memory ◽  
Preisach Model ◽  
Discrete Form ◽  
Nonlinear Characteristics ◽  
Shape Memory Alloy Actuator ◽  
Sma Actuator ◽  
Identification Model

Shape Memory Alloy is a material used to designing actuators. These actuators have many advantages. They are light, strong and silent. They are building in laboratory and tested because beside advantages they have disadvantages too. SMA actuators have nonlinear characteristics with hysteresis loop.In the first part of the paper Shape Memory Alloys are shortly described. Next mathematical model was formulated. In the paper the Preisach model was developed. Discrete form of the model was considered and implemented. After parameter identification model was implemented in LabView. Tests of the model were conducted and results were worked. Obtained characteristics of the SMA actuator are shown in the paper. At the end of the paper the conclusions were formulated.

Longitudinal Instability in Braked Landing Gear

1981 ◽  
Vol 103 (3) ◽  
pp. 259-265 ◽  
Author(s):  
R. R. Allen ◽  
R. C. O’Massey
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Analytical Methods ◽  
Design Guidelines ◽  
Landing Gear ◽  
Nonlinear Mathematical Model ◽  
Nonlinear Characteristics ◽  
Aircraft Landing ◽  
Design Variables ◽  
Aircraft Landing Gear

An instability in the form of a self-excited, bounded longitudinal oscillation may occur in aircraft landing gear when one or more wheels lock due to excessive braking. The instability usually appears at ground speeds below 40 knots (20 m/s) and results from interaction between structural elasticity and the nonlinear characteristics of tire-runway friction. A nonlinear mathematical model is developed to study the dynamics of this divergence in a braked, dual tire landing gear. Analytical methods are presented to determine critical ground speeds in terms of runway friction characteristics and to predict the amplitude of steady-state oscillations. The effect of design variables on longitudinal stability is evaluated and design guidelines are presented which insure reduction of the severity of this divergent dynamic behavior.

scholarly journals Математична модель антени з нелінійними характеристиками для розрахунку елект-ромагнітного поля у зоні Френеля

2021 ◽  
pp. 46-58
Author(s):  
Дмитро Вячеславович Грецьких ◽  
Василь Олександрович Алєксєєв ◽  
Андрій Володимирович Гомозов ◽  
Віктор Олександрович Катрич ◽  
Михайло Васильович Нестеренко
Keyword(s):  
Mathematical Model ◽  
Electromagnetic Compatibility ◽  
Phase Distribution ◽  
Mutual Influence ◽  
Fresnel Zone ◽  
Nonlinear Effects ◽  
Arbitrary Field ◽  
Mathematical Methods ◽  
Nonlinear Characteristics ◽  
Transmitting Antenna

The paper presents a mathematical model of radio-electronic systems (RES), which include antennas and their excitation paths with nonlinear characteristics. The model provides acceptable accuracy of RES quality indicator analysis and electromagnetic compatibility (EMC) for further practical design. General purpose: the development of a mathematical model of a transmitting multi-input radiating structure with nonlinear characteristics under the Fresnel zone. Objective: choice justification of a structural schema of a radiating multi-input system with a radiator that has a distributed nonlinear surface impedance; obtaining the nonlinear integral equations (NIE) related to the current density for radiators with distributed nonlinearity, excited by an arbitrary field distribution for solving the general analysis problem; obtaining a ratio for calculating focused electromagnetic fields (EMF) created by multi-input radiating structures with nonlinear characteristics in the Fresnel zone. The methods used in the paper are mathematical methods of electrodynamics and antennas theory with nonlinear elements (ANE), theory of microwave circuits, and multipoles. The following results were obtained. An electrodynamics approach is proposed to analyze the entire set of nonlinear effects arising in transmitting multi-input radiating structures with nonlinear characteristics. It allows considering the mutual influence of the transmitting and receiving antennas with nonlinear characteristics in the system itself and the electrodynamics interaction of the transmitting antenna with nonlinear characteristics with RES for other purposes. Component equations (NIE) of multi-input radiating structures that establish the relationship of amplitude-phase distribution at the inputs of radiators with distributed nonlinearity and amplitude-phase distribution on their surfaces are obtained. A mathematical model of multi-input radiator structures with nonlinear characteristics in the Fresnel zone for analysis purposes has been produced. Conclusions. The scientific novelty of the obtained results is as follows: a generalized theory of transmitting antennas of arbitrary configuration with nonlinear characteristics in the Fresnel zone, which makes it possible to analyze the characteristics of these antennas considering the positive and negative (beneficial and adverse) nonlinear effects that arise in them.

scholarly journals A Novel Voltage-Controlled Tri-Valued Memristor and Its Application in Chaotic System

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xiaoyuan Wang ◽  
Xue Zhang ◽  
Meng Gao
Keyword(s):  
Mathematical Model ◽  
Nonlinear Systems ◽  
Chaotic System ◽  
Dynamic Characteristics ◽  
Chaotic Systems ◽  
Nonlinear Element ◽  
Nonlinear Characteristics ◽  
Nanometer Size ◽  
New Chaotic System

Memristor is a kind of passive nonlinear element, which is widely used in nonlinear systems, especially chaotic systems, because of its nanometer size, nonvolatile property, and good nonlinear characteristics. Compared with general chaotic systems, chaotic systems based on memristors have richer dynamic characteristics. However, the current research mainly focuses on the binary and continuous chaotic systems based on memristors, and studies on the tri-valued and multi-valued memristor chaotic systems are relative scarce. For this reason, a mathematical model of tri-valued memristor is proposed, and the circuit characteristics of the model are studied. Furthermore, based on this model, a new chaotic system is designed and analyzed. This innovation enriches the types of chaotic systems and lays the foundation for the application of tri-valued and multi-valued memristors in nonlinear systems.

Universal Mathematical Model of Mesoscale Eddy

2021 ◽  
pp. 19-29
Author(s):  
Shu-Tang Liu ◽  
Yu-Pin Wang ◽  
Zhi-Min Bi ◽  
Yin Wang
Keyword(s):  
Mathematical Model ◽  
Mesoscale Eddy

scholarly journals Modelling of an Esaki Tunnel Diode in a Circuit Simulator

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Nikhil M. Kriplani ◽  
Stephen Bowyer ◽  
Jennifer Huckaby ◽  
Michael B. Steer
Keyword(s):  
Mathematical Model ◽  
Intermediate State ◽  
Tunnel Diode ◽  
Nonlinear Characteristic ◽  
Nonlinear Characteristics ◽  
Circuit Simulator ◽  
Strongly Nonlinear ◽  
State Variable

A method for circuit-level modelling a physically realistic Esaki tunnel diode model is presented. A paramaterisation technique that transforms the strongly nonlinear characteristic of a tunnel diode into two relatively modest nonlinear characteristics is demonstrated. The introduction of an intermediate state variable results in a physically realistic mathematical model that is not only moderately nonlinear and therefore robust, but also single-valued.

scholarly journals Effect of joint and isolated irregularities of the track on the wear of rails in curves

2018 ◽  
Vol 230 ◽  
pp. 01012 ◽  
Author(s):  
Dmytro Potapov ◽  
Sergij Panchenko ◽  
Yaroslav Leibuk ◽  
Yuseph Tuley ◽  
Pavel Plis
Keyword(s):  
Mathematical Model ◽  
Common Type ◽  
Rolling Stock ◽  
Dynamic Processes ◽  
Spatial Dynamic ◽  
Nonlinear Characteristics ◽  
Plan View ◽  
Numerical Studies ◽  
Mathcad Software ◽  
Work Effect

The purpose of the work is to identifying causes of intensive lateral wear of rails and other track failures in short radius curves using numerical methods. The study has been conducted for the most common type of rolling stock: four-axle freight cars on TsNII-Ch3 bogies, transportation of which makes 75-90% of freight load of the track sections. Thus, it is the effect of these cars which is the main cause of the above disorders. To solve the problem, effect of the following parameters of the track plan on dynamic processes of interaction of the track and rolling stock was investigated in the work: effect of the curves radius, the unbalanced accelerations and the width of the track; effect of local joint and smooth irregularities of the track in plan view. The results of numerical studies. A mathematical model of the spatial dynamic system “vehicle-track” has been used to perform the study, which is based on the design diagrams of the track in the form of long rail beams resting on multiple dissipative elastic supporting sleepers with nonlinear characteristics. This model is implemented in the MathCAD software system.

scholarly journals SIMULATION OF TRUCKING MODE CARS WITH A COMBINED ELASTIC ELEMENT IN THE REAR AXLE SUSPENSION

2021 ◽  
Vol 4 (4) ◽  
pp. 114-119
Author(s):  
Vladimir Pryadkin ◽  
Aleksandr Zavyalov
Keyword(s):  
Mathematical Model ◽  
Numerical Experiment ◽  
Elastic Element ◽  
Rear Axle ◽  
Nonlinear Characteristic ◽  
Nonlinear Characteristics ◽  
The Mathematical Model ◽  
Elastic Elements

The article analyzes elastic elements with a nonlinear characteristic. To improve the smoothness of a truck, a combined elastic element is proposed, including a semi-eleptic spring and an air cylinder, for installation in the rear axle suspension of a car. In order to assess the effect of a combined elastic element with a nonlinear characteristic on the smoothness of the ride, a mathematical model has been developed. The mathematical model allows for a numerical experiment taking into account the nature of the interaction of tires with unevenness of the roadway and the nonlinear characteristics of the combined elastic element.

scholarly journals Metabolism in replacement chickens at different ratios of arginine and lysine

2020 ◽  
Vol 10 (5) ◽  
pp. 127-132
Author(s):  
I. Ibatullin ◽  
M. Kryvenok ◽  
I. Ilchuk
Keyword(s):  
Mathematical Model ◽  
Amino Acids ◽  
Amino Acid ◽  
Linear Dependence ◽  
Regression Equations ◽  
Nonlinear Characteristics ◽  
Modeling Methods ◽  
Growth Development ◽  
Poultry Diets ◽  
Different Levels

The influence of different levels of arginine and lysine in compound feeds of replacement chickens on their growth, development and metabolism was studied. The effective ratio of arginine to lysine in the diets of replacement chickens was experimentally established, which, depending on the rearing period, was: 1.0:1 for 1-3 weeks, 1.1:1 for 4-8 weeks, 1.2:1 for 16 weeks and 1.2:1 for 17-18 weeks. It was found that the change in the ratio of arginine and lysine in poultry diets has a much higher degree of influence on their productivity, digestibility of feed nutrients, assimilation and efficiency of amino acids than changes in the levels of these amino acids. It was found that the ratio of arginine and lysine in the last period of rearing chickens (16-18 weeks) to a lesser extent affects the productivity of replacement young (R2=0.59) compared to the first (R2=0.96) and second periods of rearing (R2=0.65). The growth of replacement young during all periods of the experiment and the nature of the effect of changes in levels and ratios of these amino acids in feed depending on age and productivity, described by a mathematical model with nonlinear characteristics (polynomial trend line), which has a higher value of approximation (R2) linear dependence. The use of modern modeling methods and the proposed regression equations allow to predict the content of amino acids in feed for replacement young poultry in accordance with the program of their cultivation and amino acid composition of feed.

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