METHODS OF SOLVING THE STABILITY QUARTIC AND DETERMINATION OF DYNAMIC STABILITY CRITERIA

1980 ◽  
pp. 207-215
Keyword(s):  
Dynamic Stability ◽  
Stability Criteria ◽  
The Stability

Dynamic Stability of a Rotor Filled or Partially Filled With Liquid

1996 ◽  
Vol 63 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Wen Zhang ◽  
Jiong Tang ◽  
Mingde Tao
Keyword(s):  
Dynamic Stability ◽  
Dynamic Pressure ◽  
Flow Analysis ◽  
Previous Literature ◽  
Stability Criteria ◽  
Stability Boundaries ◽  
Planar Flow ◽  
Harmonic Motion ◽  
Analytical Stability ◽  
The Stability

The dynamic stability of a high-spinning liquid-filled rotor with both internal and external damping effects involved in is investigated in this paper. First, in the case of the rotor subjected to a transverse harmonic motion, the dynamic pressure of the liquid acting on the rotor is extracted through a planar flow analysis. Then the equation of perturbed motion for the liquid-filled rotor is derived. The analytical stability criteria as well as the stability boundaries are given. The results are extensions of those given by previous literature.

Dynamic Stability of Nonlinear Antisymmetrically-Laminated Cross-Ply Rectangular Plates

1989 ◽  
Vol 56 (2) ◽  
pp. 375-381 ◽  
Author(s):  
Andrzej Tylikowski
Keyword(s):  
Asymptotic Stability ◽  
Dynamic Stability ◽  
Material Properties ◽  
Stability Problem ◽  
Large Deflection ◽  
Direct Method ◽  
Rectangular Plates ◽  
Stability Criteria ◽  
The Stability ◽  
Liapunov's Direct Method

The dynamic stability problem is solved for rectangular plates that are laminated antisymmetrically about their middle plane and compressed by time-dependent deterministic or stochastic membrane forces. Moderately large deflection equations taking into account a coupling of in-plane and transverse motions are used. The asymptotic stability and almost-sure asymptotic stability criteria involving a damping coefficient and loading parameters are derived using Liapunov’s direct method. A relation between the stability of nonlinear equations and linearized ones is analyzed. An influence on the number of orthotropic layers, material properties for different classes of parametric excitation on stability domains is shown.

scholarly journals Stability Criterion for Dynamic Gaits of Quadruped Robot

2018 ◽  
Vol 8 (12) ◽  
pp. 2381 ◽  
Author(s):  
Yan Jia ◽  
Xiao Luo ◽  
Baoling Han ◽  
Guanhao Liang ◽  
Jiaheng Zhao ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Stability Criterion ◽  
Quadruped Robot ◽  
Stability Criteria ◽  
Irregular Terrain ◽  
Quadruped Robots ◽  
Simulation Results ◽  
Zero Moment ◽  
The Stability ◽  
Dynamic Gait

Dynamic-stability criteria are crucial for robot’s motion planning and balance recovery. Nevertheless, few studies focus on the motion stability of quadruped robots with dynamic gait, none of which have accurately evaluated the robots’ stability. To fill the gaps in this field, this paper presents a new stability criterion for the motion of quadruped robots with dynamic gaits running over irregular terrain. The traditional zero-moment point (ZMP) is improved to analyze the motion on irregular terrain precisely for dynamic gaits. A dynamic-stability criterion and measurement are proposed to determine the stability state of the robot and to evaluate its stability. The simulation results show the limitations of the existing stability criteria for dynamic gaits and indicate that the criterion proposed in this paper can accurately and efficiently evaluate the stability of a quadruped robot using such gaits.

scholarly journals ДИНАМІЧНА РЕАКЦІЯ ТА СТІЙКІСТЬ ПОШКОДЖЕНОЇ КОНСТРУКЦІЇ ТРАНСПОРТНОГО ЛІТАКА

2020 ◽  
pp. 173-180
Author(s):  
Є. Ю. Іленко ◽  
В. М. Онищенко
Keyword(s):  
Dynamic Stability ◽  
Equations Of Motion ◽  
Initial Perturbation ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Ultimate State ◽  
Main Method ◽  
Operating Load ◽  
The Stability

In the process of designing and operating the aircraft, it is important to determine the ultimate state of the structure, taking into account the dynamic load of the structure and its stability. The ultimate state of the structure is characterized by damage, in which the structure still retains the ability to withstand without catastrophic destruction of the maximum operating load. The main method of studying the stability of the structure is the dynamic method. It allows us to investigate the perturbed motion of a structure as a nonconservative system for some initial perturbation. The monotonic departure of the system from the equilibrium position or its oscillations with increasing amplitudes indicate the instability of the structure. The paper analyzes the effect of damage to the aircraft structure on its dynamic stability based on the determination of the dynamic response of the aircraft to some non-stationary perturbation, for example, on the action of a turbulent atmosphere. The method of computational analysis is used to study the dynamic stability of the structure. The basis of this method is mathematical modeling (MM) of the operation of the aircraft in the form of a system of equations of motion and deformation of the structure. The problem of dynamic aeroelasticity is considered - the behavior of the elastic damaged structure of the aircraft in the air flow to the initial perturbation. On the basis of computer simulation, the dynamic stability of the elastic structure, its oscillating or quasi-static (aperiodic) deformation motion within the flight range of the aircraft is estimated. On the basis of parametric researches the limits of instability of a design at the set damages for typical operating conditions are estimated. The relevance of the direction focused on the creation and advanced operation of MM aircraft - their mathematical backups in the process of design and operation of aircraft due to the complexity and limited capabilities of ground experimental installations and flight experiment. It is noted that the condition for the application of this method is the formed MM operation of the aircraft and the availability of information on the mass-inertial, stiffness and aerodynamic characteristics of the aircraft.

Dynamic Stability of a Pendulous Missile Suspension System

1962 ◽  
Vol 29 (2) ◽  
pp. 276-282
Author(s):  
V. Chobotov
Keyword(s):  
Differential Equations ◽  
Dynamic Stability ◽  
Periodic Coefficient ◽  
Suspension System ◽  
Second Order ◽  
Stability Criteria ◽  
Parametrically Excited ◽  
Second Order Differential Equations ◽  
The Stability

The stability criteria for a missile on a pendulous support are derived for the case of parametrically excited motions of the support. The suspension system is described by two linear second-order differential equations with a periodic coefficient. The analysis is carried out by means of the first method of Liapunov. The results are somewhat modified, however, to obtain greater generality without which the technique is too laborious to be useful.

Plate subjected to an out-of-plane follower force

2002 ◽  
Vol 216 (9) ◽  
pp. 913-921
Author(s):  
J Genin ◽  
W Xu
Keyword(s):  
Dynamic Stability ◽  
Follower Force ◽  
Jet Engine ◽  
Engine Thrust ◽  
Out Of Plane ◽  
The Stability

The stability of bending-torsional equilibrium of a uniform plate subjected to an out-of-plane follower force is studied in this paper. The resulting system approximates to a wing subjected to the thrust of a jet engine. Attention is focused on the determination of the dynamic stability of the wing as a function of engine thrust. Criteria are established for the determination of the maximum allowable value of the engine thrust.

scholarly journals Consideration of International Maritime Organization (IMO) proposals when developing new requirements of the Russian Register of Shipping to the stability of ship

2020 ◽  
pp. 39-44
Author(s):  
Р.В. Борисов ◽  
М.А. Кутейников ◽  
А.А. Лузянин ◽  
В.Р. Самойлов
Keyword(s):  
Stability Diagram ◽  
Stability Criteria ◽  
Short Term ◽  
Reliable Determination ◽  
Intact Stability ◽  
Domestic Practice ◽  
The Stability ◽  
New Generation

При создании норм для морских судов, попадающих в разнооб­разные гидрометеорологические условия, достоверный расчет кренящих моментов затруднителен, и задача определения мини­мально допустимых характеристик остойчи­вости (критериев) решалась путем анализа статистических данных об остойчивости судов, успешно эксплуатировавшихся или потерпевших аварию вследствие недоста­точной остойчивости. Применительно к тре­бованиям ИМО в качестве нормируемых характеристик остойчивости были приняты характеристики начальной остойчивости и диаграммы статической остойчивости. В настоящее время в ИМО ведется активная работа по созданию критериев остойчивости нового поколения, учитывающих более широкий круг явлений, опасных с точки зрения остойчивости судна, Действующие нормы Кодекса ИМО по остойчивости 2008 года их не учитывают. С учетом близости отечественных и международных методик оценки кратковременных и долговременных показателей мореходности анализируются результаты этой работы и оценивается возможность использования предлагаемых в ИМО подходов в отечественной практике нормирования море­ходности. For sea going ships operated in different hydro meteorological conditions reliable determination of heeling moments is difficult and the task of obtaining minimum allowable stability characteristics (criteria) was done by statistical stability analysis of ships successfully operated or capsized due to lack of stability. At IMO requirements intact stability was regulated by meta centric height ana stability diagram requirements. Currently, IMO is actively working on creating new generation stability criteria, which take into account a wider range of phenomena hazardous in terms of ship stability. The current standards of the IMO Stability Code 2008 do not take them into account. Considering the proximity of domestic and international methods for assessing short-term and long-term seaworthiness indices, the results of this work are analyzed and the possibility of using the approaches proposed by IMO in the domestic practice of seaworthiness rationing is evaluated.

Determining the Norton’s Equivalent Model of Distribution System with Distributed Generation (DG) for Stability Analysis

2019 ◽  
Vol 12 (2) ◽  
pp. 190-198
Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar
Keyword(s):  
Distributed Generation ◽  
Normal Condition ◽  
Distribution System ◽  
Distribution Networks ◽  
Equivalent Model ◽  
Stability Factor ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Issues

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

Synthesis and solvatochromic studies of 2- amino-3-phenolazo1-(4-sulfophenyl)-3-methyi-5-pyrozolone and use it for the determination of trace amount of Nickel (II) in blood samples

2016 ◽  
Vol 5 (10) ◽  
pp. 4920
Author(s):  
Amar M. Ali ◽  
Hussain. J. Mohammed*
Keyword(s):  
Stability Constant ◽  
Trace Amount ◽  
Benzenesulfonic Acid ◽  
Determination Method ◽  
Blood Samples ◽  
Determination Of Nickel ◽  
Normal Human ◽  
The Stability ◽  
Normal Human Blood

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood. 

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