On Randomly Excited Hysteretic Structures

1990 ◽  
Vol 57 (2) ◽  
pp. 442-448 ◽  
Author(s):  
G. Q. Cai ◽  
Y. K. Lin
Keyword(s):  
Energy Dissipation ◽  
Narrow Band ◽  
Probability Distributions ◽  
Gaussian White Noise ◽  
Energy Balancing ◽  
Dissipation Energy ◽  
System Parameters ◽  
Hysteretic Systems ◽  
Approximate Probability ◽  
Simulation Results

Approximate probability distributions of certain response variables are obtained for hysteretic systems under Gaussian white-noise excitations. The approximate method used is a generalization of a dissipation-energy-balancing procedure, developed previously for nonlinear but basically nonhysteretic systems. Some new issues related particularly to hysteresis models are explained and resolved. The method is applicable to either bilinear or smooth-type hysteresis without the restriction that the response be a narrow-band process or the energy dissipation be small. Comparison of computed results with available simulation results indicates that the proposed method is accurate for wide ranges of excitation levels and system parameters.

Equivalent Nonlinear System Method for Stochastically Excited Hamiltonian Systems

1994 ◽  
Vol 61 (3) ◽  
pp. 618-623 ◽  
Author(s):  
W. Q. Zhu ◽  
T. T. Soong ◽  
Y. Lei
Keyword(s):  
Nonlinear System ◽  
Nonlinear Systems ◽  
White Noise ◽  
Probability Density ◽  
Hamiltonian Systems ◽  
Gaussian White Noise ◽  
Energy Balancing ◽  
Dissipation Energy ◽  
System Method ◽  
Approximate Probability

An equivalent nonlinear system method is presented to obtain the approximate probability density for the stationary response of multi-degree-of-freedom nonlinear Hamiltonian systems to Gaussian white noise parametric and/or external excitations. The equivalent nonlinear systems are obtained on the basis of one of the following three criteria: least mean-squared deficiency of damping forces, dissipation energy balancing, and least mean-squared deficiency of dissipation energies. An example is given to illustrate the application and validity of the method and the differences in the three equivalence criteria.

Equivalent Nonlinear System Method for Stochastically Excited and Dissipated Integrable Hamiltonian Systems

1997 ◽  
Vol 64 (1) ◽  
pp. 209-216 ◽  
Author(s):  
W. Q. Zhu ◽  
Y. Lei
Keyword(s):  
Nonlinear System ◽  
Nonlinear Systems ◽  
Hamiltonian Systems ◽  
Energy Balancing ◽  
Integrable Hamiltonian Systems ◽  
Dissipation Energy ◽  
System Method ◽  
Special Cases ◽  
Approximate Probability ◽  
White Noises

An equivalent nonlinear system method is proposed to obtain the approximate probability density for the stationary response of multi-degree-of-freedom integrable Hamiltonian systems with linear and (or) nonlinear dampings and subject to external and (or) parametric excitations of Gaussian white noises. The equivalent nonlinear systems are obtained on the basis of one of the following three criteria: least mean-squared difference in damping forces, dissipation energy balancing, or least mean-squared difference in dissipation energies. Two examples are given to illustrate the application and validity of the method and the differences in the three equivalence criteria. The method is also extended to a more general class of systems which include the stochastically excited and dissipated integrable Hamiltonian systems as special cases.

ADAPTIVE IDENTIFICATION ALGORITHMS FOR AR SYSTEM DRIVEN BY CHAOTIC SEQUENCE

2003 ◽  
Vol 13 (04) ◽  
pp. 963-972 ◽  
Author(s):  
BAO-YUN WANG ◽  
T. W. S. CHOW ◽  
K. T. NG
Keyword(s):  
Communication System ◽  
Adaptive Algorithms ◽  
Chaotic Sequence ◽  
Estimation Accuracy ◽  
Chaotic Communication ◽  
Adaptive Identification ◽  
System Parameters ◽  
Chaotic Sequences ◽  
Simulation Results ◽  
Typical Method

In this article the identification of AR system driven by chaotic sequences is addressed. This problem emerges in chaotic communication system, in which chaos-modulated signal passes through a channel described as an AR system. Two adaptive algorithms are presented to tackle this problem. Compared with the existing algorithms such as MPSV and MNPE, the proposed algorithms have very low computational complexities and can be used to track the system parameters in a slowly time-variant environment. The obtained simulation results illustrate that the proposed scheme can offer a better estimation accuracy than the conventional typical method in the high SNR case.

Calculation of Nonlinear Systems Under Narrow Band Excitation Using Equivalent Linearization and Path Continuation

2021 ◽  
Author(s):  
Alwin Förster ◽  
Lars Panning-von Scheidt
Keyword(s):  
Nonlinear Systems ◽  
Narrow Band ◽  
Gaussian White Noise ◽  
Random Excitation ◽  
Mean Value ◽  
Equivalent Linearization ◽  
Efficient Procedure ◽  
Stochastic Excitations ◽  
Wide Range ◽  
The One

Abstract Turbomachines experience a wide range of different types of excitation during operation. On the structural mechanics side, periodic or even harmonic excitations are usually assumed. For this type of excitation there are a variety of methods, both for linear and nonlinear systems. Stochastic excitation, whether in the form of Gaussian white noise or narrow band excitation, is rarely considered. As in the deterministic case, the calculations of the vibrational behavior due to stochastic excitations are even more complicated by nonlinearities, which can either be unintentionally present in the system or can be used intentionally for vibration mitigation. Regardless the origin of the nonlinearity, there are some methods in the literature, which are suitable for the calculation of the vibration response of nonlinear systems under random excitation. In this paper, the method of equivalent linearization is used to determine a linear equivalent system, whose response can be calculated instead of the one of the nonlinear system. The method is applied to different multi-degree of freedom nonlinear systems that experience narrow band random excitation, including an academic turbine blade model. In order to identify multiple and possibly ambiguous solutions, an efficient procedure is shown to integrate the mentioned method into a path continuation scheme. With this approach, it is possible to track jump phenomena or the influence of parameter variations even in case of narrow band excitation. The results of the performed calculations are the stochastic moments, i.e. mean value and variance.

Global Analysis of the Double Impact Oscillator Dynamics

1999 ◽  
Author(s):  
František Peterka
Keyword(s):  
Global Analysis ◽  
Impact Oscillator ◽  
System Parameters ◽  
Impact Oscillators ◽  
Real Value ◽  
Simulation Results ◽  
The Impact ◽  
Impact Motion ◽  
Double Impact ◽  
Phase Motion

Abstract The double impact oscillator represents two symmetrically arranged single impact oscillators. It is the model of a forming machine, which does not spread the impact impulses into its neighbourhood. The anti-phase impact motion of this system has the identical dynamics as the single system. The in-phase motion and the influence of asymmetries of the system parameters are studied using numerical simulations. Theoretical and simulation results are verified experimentally and the real value of the restitution coefficient is determined by this method.

scholarly journals The Sum and Difference of Two Lognormal Random Variables

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
C. F. Lo
Keyword(s):  
Stochastic Process ◽  
Probability Distributions ◽  
Operator Splitting ◽  
Splitting Method ◽  
Unified Approach ◽  
New Approach ◽  
Numerical Examples ◽  
Operator Splitting Method ◽  
Approximate Probability ◽  
Analytical Series

We have presented a new unified approach to model the dynamics of both the sum and difference of two correlated lognormal stochastic variables. By the Lie-Trotter operator splitting method, both the sum and difference are shown to follow a shifted lognormal stochastic process, and approximate probability distributions are determined in closed form. Illustrative numerical examples are presented to demonstrate the validity and accuracy of these approximate distributions. In terms of the approximate probability distributions, we have also obtained an analytical series expansion of the exact solutions, which can allow us to improve the approximation in a systematic manner. Moreover, we believe that this new approach can be extended to study both (1) the algebraic sum ofNlognormals, and (2) the sum and difference of other correlated stochastic processes, for example, two correlated CEV processes, two correlated CIR processes, and two correlated lognormal processes with mean-reversion.

scholarly journals Двумерные брэгговские резонаторы на основе планарных диэлектрических волноводов (от теории к модельному тестированию)

2019 ◽  
Vol 53 (10) ◽  
pp. 1315
Author(s):  
Н.С. Гинзбург ◽  
Н.Ю. Песков ◽  
В.Ю. Заславский ◽  
Е.Р. Кочаровская ◽  
А.М. Малкин ◽  
...  
Keyword(s):  
Narrow Band ◽  
Bragg Reflection ◽  
Dielectric Waveguides ◽  
Wavelength Band ◽  
Reflection Band ◽  
Millimeter Wavelength ◽  
Bragg Structures ◽  
Significant Interest ◽  
Simulation Results ◽  
Analytical Approaches

Using analytical approaches and CST Microwave Studio 3D simulations, we have undertaken a theoretical analysis of electrodynamical characteristics of 2D Bragg structures based on planar oversized dielectric waveguides with double-periodical corrugation. Such structures are of significant interest for obtaining directed narrow-band radiation in heterolasers with large dimensions of an active area. Modeling electrodynamical experiments on 'cold' testing of such structures in millimeter wavelength band were conducted. Fine agreement between the experimental results and the simulation results was demonstrated which includes the presence of the highest-quality mode inside the Bragg reflection band in absence of the periodicity defects.

An Energy Balanced Routing Hole and Network Partitioning Mitigation Model for Homogeneous Hierarchical Wireless Sensor Networks

2020 ◽  
Vol 12 (1) ◽  
pp. 28-42
Author(s):  
Nnaemeka Chiemezie Onuekwusi ◽  
Michael Chukwudi Ndinechi ◽  
Gordon Chiagozie Ononiwu ◽  
Onyebuchi Chikezie Nosiri
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Energy Dissipation ◽  
Cluster Head ◽  
Wireless Sensor ◽  
Switching Network ◽  
Minimal Distance ◽  
Network Partitioning ◽  
Energy Balancing ◽  
Hierarchical Wireless Sensor Networks

This article addresses the challenges of routing hole and network partitioning often experienced in hierarchical wireless sensor networks (WSNs). This developed model classifies network nodes into sets for effective energy management and formulates two cluster networks namely: switching and non-switching networks. Both networks are considered homogeneous and static WSNs and adopted approaches of residual energy, multi-hop and minimal distance as routing decision parameters. The switching network in addition introduces an energy switching factor as a major decision parameter for the switching of cluster head roles amongst cluster nodes. Network simulation was done using Truetime 2.0 and energy dissipation of the respective nodes and cluster heads was observed against a threshold. Results showed the introduction of the energy switching factor gave a significant energy balancing effect as nodes exhibited uniform energy dissipation. Furthermore, the residual energies for most nodes were above the threshold eliminating the possibility of the presence of routing hole and network partitioning.

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