Research on Lyapunov Exponent of Chaos Feature in Different Stress Stage of Concrete Joint System

2010 ◽  
Vol 143-144 ◽  
pp. 120-124 ◽  
Author(s):  
Jun Wei Song
Keyword(s):  
Compressive Strength ◽  
Steady State ◽  
Stability Criterion ◽  
System Stability ◽  
Stress System ◽  
Chaotic State ◽  
Whole Process ◽  
Strain Stress ◽  
The Stability ◽  
Relationship Of

: According to the research on whole curves of strain-stress of concrete materials, the paper illustrates in evidence features of stages and shows that the discrete feature of curve often occurs in strain-softening stage. After chaotic dynamic analysis of testing datas, it presents that system of whole process of strain-stress evolves from ordered steady state to low chaotic state and then to high chaotic state along with increase of compressive strength. The linear relationship of strain- stress grows evident and the system evolves from strong ordered steady state to low chaos state. The strain-stress system before compressive strength peak is basically in weak chaotic state. The is proposed to be the stability criterion of concrete features in different stress stages, and the is regarded as the representative value of the system stability degree. The calculation of example shows that the stability criterion definited by the proposed method is consistent with the actural situation.

Chaotic Characteristic Analysis of Concrete Fracture System Based on Lyapunov Exponent Stability Criterion

2013 ◽  
Vol 423-426 ◽  
pp. 1105-1109
Author(s):  
Jun Wei Song
Keyword(s):  
Compressive Strength ◽  
Steady State ◽  
Stability Criterion ◽  
System Stability ◽  
Stress System ◽  
Characteristic Analysis ◽  
Chaotic State ◽  
Whole Process ◽  
Strain Stress ◽  
The Stability

According to the research on whole curves of strain-stress of concrete materials, the paper illustrates in evidence features of stages and shows that the discrete feature of curve often occurs in strain-softening stage. After chaotic dynamic analysis of testing datas, it presents that system of whole process of strain-stress evolves from ordered steady state to low chaotic state and then to high chaotic state along with increase of compressive strength. The linear relationship of strain-stress grows evident and the system evolves from strong ordered steady state to low chaos state. The strain-stress system before compressive strength peak is basically in weak chaotic state. Theis proposed to be the stability criterion of concrete features in different stress stages, and the is regarded as the representative value of the system stability degree. The calculation of example shows that the stability criterion definited by the proposed method is consistent with the actural situation.

The flow of a micropolar liquid layer down an inclined plane

1968 ◽  
Vol 64 (2) ◽  
pp. 513-526 ◽  
Author(s):  
A. J. Willson
Keyword(s):  
Thin Films ◽  
Steady State ◽  
Liquid Layer ◽  
Stability Criterion ◽  
Long Waves ◽  
Inclined Plane ◽  
The Stability ◽  
Micropolar Liquid

AbstractConsideration is given to the flow of a micropolar liquid down an inclined plane. The steady state is analysed and Yih's technique is employed in an investigation of the stability of this flow with respect to long waves. Detailed calculations are given for thin films and it is shown that the micropolar properties of the liquid play an important role in the stability criterion.

scholarly journals Desain dan analisis pengaruh parameter PI dan variasi kecepatan pada respon sistem kontrol arah hadap prototype kendaraan listrik

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Afif Caesar Distara ◽  
Fatkhur Rohman
Keyword(s):  
Control System ◽  
Steady State ◽  
Electric Vehicles ◽  
Rise Time ◽  
Small Error ◽  
Settling Time ◽  
System Stability ◽  
Prototype System ◽  
Stability Parameters ◽  
The Stability

Electric vehicles are alternative vehicles that carry energy efficient. At this time the dominant vehicle uses ordinary wheels so that it will become an obstacle in the maneuver function that requires movement in various directions. With mechanum wheels the vehicle can move in various directions by adjusting the direction of rotation of each wheel. The problem is choosing the right control system for the control system needed by the vehicle. The purpose of this study is to determine and analyze the effect of variations in the value of PI (Proportional Integral) and speed of the vehicle to the stability response of the system to control the direction of prototype electric vehicles. This study method is an experiment that is by giving a treatment, then evaluating the effects caused by the research object. The results of this study can be concluded that the variation of PI constant values and speed variations have an effect on the stability parameters of the system, namely rise time, settling time, overshot, and steady state error. To get the best system stability response results can use the constant value PI Kp = 2; and Ki = 17; where the stability response of the system for direction control at each speed condition has a fairly good value with a fast rise time, fast settling time, small overshot and a small error steady state compared to other PI constant values in this study.Keywords: mechanum wheel, PI control, direction, prototype, system stability

Frequency-domain analysis method for analyzing and improving the steady-state characteristics of microcantilever in tapping-mode atomic force microscopy

2018 ◽  
Vol 82 (1) ◽  
pp. 10701
Author(s):  
Xiaohui Gu ◽  
Lining Sun ◽  
Changhai Ru
Keyword(s):  
Steady State ◽  
Frequency Domain ◽  
Stability Margin ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
System Stability ◽  
Analysis Method ◽  
External Interference ◽  
Tapping Mode ◽  
The Stability

In tapping-mode AFM, the steady-state characteristics of microcantilever are extremely important to determine the AFM performance. Due to the external excitation signal and the tip-sample interactions, the solving process of microcantilever motion equation will become very complicated with the traditional time-domain analysis method. In this paper, we propose the novel frequency-domain analysis method to analyze and improve the steady-state characteristics of microcantilever. Compared with the previous methods, this new method has three prominent advantages. Firstly, the analytical expressions of amplitude and phase of cantilever system can be derived conveniently. Secondly, the stability of the cantilever system can be accurately determined and the stability margin can be obtained quantitatively in terms of the phase margin and the magnitude margin. Thirdly, on this basis, external control mechanism can be devised quickly and easily to guarantee the high stability of the cantilever system. With this novel method, we derive the frequency response curves and discuss the great influence of the intrinsic parameters on the system stability, which provides theoretical guidance for selecting samples to achieve better AFM images in the experiments. Moreover, we introduce a new external series correction method to significantly increase the stability margin. The results indicate that the cantilever system is no longer easily disturbed by external interference signals.

Photobioreactor Stability by Phase Plane Technique Applied to Spirulina Maxima Growth

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Khaled Belkacemi ◽  
Safia Hamoudi
Keyword(s):  
Steady State ◽  
Phase Plane ◽  
Biologically Active ◽  
Raw Material ◽  
System Stability ◽  
Stable Steady State ◽  
Monod Kinetics ◽  
Spirulina Maxima ◽  
Plane Technique ◽  
The Stability

Spirulina maxima is a worthy multicellular filamentous micro-algae used as a food supplement and raw material for fine chemicals and biologically active compounds production. Intensive approach consisting of cultivating pure strains of this photoautotroph microorganism in photobioreactors is more desirable than extensive ones, largely incontrollable with regard to production stability. Determining the best reaction conditions to reach a steady state in the runway events is often needed in biological systems. For a biochemical engineer, knowing the system stability for an optimal bioreactor configuration is crucial to estimate the rate at which dependent variables grow or decay with the time reaction. The stability analysis becomes important in recycle processes in which possibility that these systems influence themselves exists. The aim of this work deals with the 1) description of the growth kinetics by a logistic and unstructured model based on Monod kinetics taking into account the maintenance in life of viable cells; 2) establishment of a dynamic growth model for Spirulina maxima cultivated in continuous lamellar photobioreactors using industrial manures as macro-nutrients; 3) determination of optimal culture conditions sustaining a stable growth of S. maxima in a system of two bioreactors in series; and 4) investigation of the dynamic stability of this multivariable system with nonlinear dynamics using phase plane technique (PPT). Although good mixing of the culture is essential for ensuring adequate supply of nutrients and prevention of the accumulation of toxic metabolites. Excessive agitation causes mechanical damage to Spirulina cells. An air flow rate of 2.5 L/min for airlift agitation represented a balance between the need to provide good mixing and to avoid cell damage. A stable steady state was achieved corresponding to a productivity of 10.8 g. m2/day when the system was supplied with 0.2 g N/L of minerals, at a dilution rate of 0.1 1/day, temperature of 30 °C under light intensity of 18 Klux. PPT as a powerful procedure successfully predicts the stability of such a complex system very well.

scholarly journals EIGENVALUE METHOD AND LINEARIZATION FOR THE STEADY STATE STABILITY ANALYSIS OF JAMSHORO THERMAL POWER PLANT (JTPP)

2020 ◽  
Vol 15 (12) ◽  
Author(s):  
Zulfiqar Ali Shahani
Keyword(s):  
Steady State ◽  
Power Plant ◽  
Power System ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Electrical Power ◽  
System Stability ◽  
Eigenvalue Method ◽  
The Stability ◽  
Steady State Stability

Electrical power system without interruption is the need of every consumer. Therefore, supplying electrical power which must be efficient, reliable and secure from any disturbance is the priority of power supply companies. But, due to changes in weather conditions and continuous load variations, small disturbances arise which may lead to severe disturbance. All electrical generating stations are interconnected, so a failure in any one unit can affect other generating units, therefore analysis is compulsory to solve the problem in the least time, and avoid a further big loss. Analysis of steady-state stability or transient stability plays a key role in a power system which helps to understand the behavior of a dynamic system. The stability problem is concerned with the behavior of the generating station when the system puts on either small or large disturbance. In this work, the steady-state stability (SSS) analysis of the Jamshoro thermal power plant (JTPP) is analyzed by using the eigenvalue method and linearization technique at four different reheat gain values. We develop a nonlinear mathematical model of JTPP and discuss its linearized form, and examine the behavior of the system stability using eigenvalues. The eigenvalue method analyzes the behavior of synchronous machine when system load varies continually. Numerical values of eigenvalues consist of either real part or real as well as imaginary parts. These eigenvalues help to understand the stability of the system, as to whether the system is stable or not.

A Stability Criterion for Parameter-Dependent Gyroscopic Systems

1999 ◽  
Vol 66 (3) ◽  
pp. 660-664 ◽  
Author(s):  
R. O. Hryniv ◽  
P. Lancaster ◽  
A. A. Renshaw
Keyword(s):  
Eigenvalue Problem ◽  
Stability Criterion ◽  
System Stability ◽  
Actual Computation ◽  
Design Changes ◽  
Engineering Problems ◽  
The Stability ◽  
Parameter Dependent ◽  
Gyroscopic Systems

A stability criterion for parameter-dependent gyroscopic systems is established and three examples are used to illustrate its application to typical engineering problems. In a number of practical situations, the criterion can be used to predict system stability with little actual computation and without solving any eigenvalue problem or approximating the eigenvalue locus. Thus, the criterion provides designers with a quick and accurate tool for assessing the stability consequences of potential design changes.

Studies on Bilateral Impedance Control Method for Teleoperation Robot

2014 ◽  
Vol 602-605 ◽  
pp. 924-927
Author(s):  
Min Ying ◽  
Xin Gao ◽  
Si Yu Han ◽  
Han Xu Sun ◽  
Qing Xuan Jia
Keyword(s):  
Stability Condition ◽  
Stability Criterion ◽  
Absolute Stability ◽  
Force Feedback ◽  
Control Method ◽  
Impedance Control ◽  
Tracking Performance ◽  
System Stability ◽  
Pd Control ◽  
The Stability

The bilateral PD control method for teleoperation robot has some defects, such as poor tracking performance and force feedback performance. This paper, based on traditional bilateral PD control method, adds an impedance controller to the master and the slave, and deduces the stability condition according to the absolute stability criterion. The simulation shows that this method can assure the system stability and improve tracking performance and force feedback performance.

scholarly journals INVESTIGATION ON DOUBLY FED INDUCTION GENERATOR STEADY STATE PARAMETERS

2013 ◽  
pp. 68-70
Author(s):  
SUNIL KUMAR ◽  
NITIN GOEL ◽  
P.R. SHARMA
Keyword(s):  
Steady State ◽  
Design Parameters ◽  
Induction Generator ◽  
Doubly Fed Induction Generator ◽  
Wind Energy Conversion ◽  
Energy Conversion System ◽  
Doubly Fed ◽  
The Stability ◽  
Relationship Of ◽  
Speed Response

In this paper steady state characteristic of a variable speed Doubly fed induction generator (DFIG) is investigated. Torque and speed is used as design parameters for DFIG. From mathematical model it is found that on increase of rotor injection voltage and resistance, the torque speed response is shifted from over synchronous to sub synchronous range. The stability of DFIG operation is entirely dependent on torque. The functional relationship of generator further validated using MATLAB and experimental model. DFIG find application mainly in wind energy conversion system.

Stability of Squeeze-Film-Damper Supported Flexible Rotors

1977 ◽  
Vol 99 (4) ◽  
pp. 545-551 ◽  
Author(s):  
M. D. Rabinowitz ◽  
E. J. Hahn
Keyword(s):  
Steady State ◽  
System Stability ◽  
Squeeze Film ◽  
Design Data ◽  
Flexible Rotors ◽  
Wide Range ◽  
Single Mass ◽  
The Stability ◽  
Rotor Mass

Assuming the short bearing approximation and symmetric motions, the stability of the steady-state synchronous operation of centrally preloaded single-mass flexible rotors supported in squeeze-film bearing dampers is theoretically investigated. The stability regions are depicted over a wide range of system parameters and allow for easy determination of the stability of existing steady-state design data. The influence of rotor flexibility, rotor speed, bearing dimensions, lubricant viscosity, rotor mass distribution, and rotor unbalance on rotor-bearing system stability may be readily seen. In the absence of pressurization, instability regions were possible even with relatively high support damping, though no instability was indicated for speeds below the support natural frequency, or for bearing eccentricity ratio <0.4 at any speed. Pressurization of the lubricant supply was found to stabilize the system over the whole range of parameters investigated, regardless of unbalance, which would then be limited only by the bearing clearance. Data are presented which enable the minimum supply pressure to ensure full film lubrication to be conveniently determined.

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