scholarly journals Stability and local bifurcation analyses of two-wheeled trailers considering the nonlinear coupling between lateral and vertical motions

2021 ◽  
Author(s):  
Hanna Zsofia Horvath ◽  
Denes Takacs
Keyword(s):  
Linear Stability ◽  
Stability Boundary ◽  
Small Scale ◽  
Hopf Bifurcations ◽  
Nonlinear Coupling ◽  
Center Manifold Reduction ◽  
Mechanical Models ◽  
Tire Forces ◽  
The Stability ◽  
Manifold Reduction

AbstractThe nonlinear dynamics of two-wheeled trailers is investigated using a spatial 4-DoF mechanical model. The non-smooth characteristics of the tire forces caused by the detachment of the tires from the ground and other geometrical nonlinearities are taken into account. Beyond the linear stability analysis, the nonlinear vibrations are analyzed with special attention to the nonlinear coupling between the vertical and lateral motions of the trailer. The center manifold reduction is performed leading to a normal form up to third degree terms. The nature of the emerging periodic solutions, and, thus, the sense of the Hopf bifurcations are verified semi-analytically and numerically. Simplified models of the trailer are also used in order to point out the practical relevance of the study. It is shown that the linearly independent pitch motion affects the sense of the Hopf bifurcations at the linear stability boundary. Namely, the constructed spatial trailer model provides subcritical bifurcations for higher center of gravity positions, while the commonly used simplified mechanical models explore the less dangerous supercritical bifurcations only. Domains of loss of contact of tires are also detected and shown in the stability charts highlighting the presence of unsafe zones. Experiments are carried out on a small-scale trailer to validate the theoretical results. A good agreement can be observed between the measured and numerically determined critical speeds and vibration amplitudes.

scholarly journals Dynamic properties of the coupled Oregonator model with delay

2013 ◽  
Vol 18 (3) ◽  
pp. 377-397
Author(s):  
Xiang Wu ◽  
Chunrui Zhang
Keyword(s):  
Hopf Bifurcation ◽  
Center Manifold ◽  
Dynamic Properties ◽  
Hopf Bifurcations ◽  
Center Manifold Reduction ◽  
Multiple Periodic Solutions ◽  
Normal Form Method ◽  
The Stability ◽  
Oregonator Model ◽  
Manifold Reduction

This work explores a coupled Oregonator model. By analyzing the associated characteristic equation, linear stability is investigated and Hopf bifurcations are demonstrated, as well as the stability and direction of the Hopf bifurcation are determined by employing the normal form method and the center manifold reduction. We also discussed the Z2 equivariant property and the existence of multiple periodic solutions. Numerical simulations are presented to illustrate the results in Section 5.

Stability, Bifurcation and Jumping Phenomenon in a 2-D Model of Supersonic Lifting Surfaces

2005 ◽  
Author(s):  
Pei Yu ◽  
Zhen Chen ◽  
Liviu Librescu ◽  
Piergiovanni Marzocca
Keyword(s):  
Nonlinear Feedback ◽  
Feedback Controls ◽  
Normal Form Theory ◽  
Center Manifold Reduction ◽  
Form Theory ◽  
Lifting Surfaces ◽  
The Stability ◽  
Parameter Values ◽  
Manifold Reduction ◽  
D Model

This paper is concerned with the linear/nonlinear aeroelastic control of 2-D supersonic lifting surfaces. Its goal is to provide the feedback control mechanism enabling one to enlarge the flight envelope by increasing the flutter speed, and also to control the character, benign/catastrophic of the flutter instability boundary. Structural and aerodynamic nonlinearities are included in the aeroelastic governing equations, and linear and nonlinear feedback controls in both plunging and pitching are employed in conjunction with proportional velocity feedback controls. The attention of the paper is focused on multiple Hopf bifurcations. In particular, the jumping phenomenon found in our previous work will be further investigated to reveal the physical implications. It is found that such a jumping occurs when the system has multiple families of limit cycles bifurcating from a same set of parameter values with multiple solutions for frequencies. The case investigated in this paper is restricted to zero structure damping. Center manifold reduction and normal form theory are applied to consider the stability of post-flutter solutions and the associated jumping phenomenon. Numerical simulations are presented to show the implications of time delay in the considered controls.

scholarly journals Center Manifold Reduction and Perturbation Method in a Delayed Model with a Mound-Shaped Cobb-Douglas Production Function

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Massimiliano Ferrara ◽  
Luca Guerrini ◽  
Giovanni Molica Bisci
Keyword(s):  
Hopf Bifurcation ◽  
Perturbation Method ◽  
Production Function ◽  
Center Manifold ◽  
Normal Form Theory ◽  
Center Manifold Reduction ◽  
Center Manifold Theorem ◽  
Form Theory ◽  
The Stability ◽  
Manifold Reduction

Matsumoto and Szidarovszky (2011) examined a delayed continuous-time growth model with a special mound-shaped production function and showed a Hopf bifurcation that occurs when time delay passes through a critical value. In this paper, by applying the center manifold theorem and the normal form theory, we obtain formulas for determining the direction of the Hopf bifurcation and the stability of bifurcating periodic solutions. Moreover, Lindstedt’s perturbation method is used to calculate the bifurcated periodic solution, the direction of the bifurcation, and the stability of the periodic motion resulting from the bifurcation.

scholarly journals Stability and bifurcation in a ratio-dependent Holling-III system with diffusion and delay

2014 ◽  
Vol 19 (1) ◽  
pp. 132-153 ◽  
Author(s):  
Wenjie Zuo ◽  
Junjie Wei
Keyword(s):  
Functional Response ◽  
Functional Differential Equations ◽  
Hopf Bifurcations ◽  
Normal Form Theory ◽  
Center Manifold Reduction ◽  
The Maximum Principle ◽  
Boundary Equilibrium ◽  
Ratio Dependent ◽  
Functional Differential ◽  
The Stability

A diffusive ratio-dependent predator-prey system with Holling-III functional response and delay effects is considered. Global stability of the boundary equilibrium and the stability of the unique positive steady state and the existence of spatially homogeneous and inhomogeneous periodic solutions are investigated in detail, by the maximum principle and the characteristic equations. Ratio-dependent functional response exhibits rich spatiotemporal patterns. It is found that, the system without delay is dissipative and uniformly permanent under certain conditions, the delay can destabilize the positive constant equilibrium and spatial Hopf bifurcations occur as the delay crosses through some critical values. Then, the direction and the stability of Hopf bifurcations are determined by applying the center manifold reduction and the normal form theory for partial functional differential equations. Some numerical simulations are carried out to illustrate the theoretical results.

Bifurcations of Time-Delay-Induced Multiple Transitions Between In-Phase and Anti-Phase Synchronizations in Neurons with Excitatory or Inhibitory Synapses

2019 ◽  
Vol 29 (11) ◽  
pp. 1950147 ◽  
Author(s):  
Li Li ◽  
Zhiguo Zhao ◽  
Huaguang Gu
Keyword(s):  
Time Delay ◽  
Inhibitory Synapses ◽  
Normal Form Theory ◽  
Center Manifold Reduction ◽  
Subthreshold Oscillations ◽  
Dynamical Behaviors ◽  
Stable Periodic ◽  
Form Theory ◽  
The Stability ◽  
Manifold Reduction

Time-delay-induced synchronous behaviors and synchronization transitions have been widely investigated for coupled neurons, and they play important roles for physiological functions. In the present study, time-delay-induced synchronized subthreshold oscillations were simulated, and the bifurcations underlying the synchronized behaviors were identified for a pair of coupled FitzHugh–Nagumo neurons. Multiple transitions between in-phase and anti-phase synchronizations induced by the time delay were simulated for the inhibitory and excitatory couplings. Subcritical or supercritical Hopf bifurcations and the stability of the Hopf-bifurcating periodic subthreshold oscillations were acquired using center manifold reduction and normal form theory. The in-phase or anti-phase synchronizations of the stable periodic subthreshold oscillations, which appear for multiple values of the time delay, were interpreted with the related eigenspace. The distributions of the different dynamical behaviors, including the synchronizations and bifurcations in the two-parameter plane of the time delay and coupling strength, were acquired for both types of synapses, and the different roles of the inhibitory and excitatory couplings on the synchronization transitions were compared.

scholarly journals Stability and Sensitive Analysis of a Model with Delay Quorum Sensing

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhonghua Zhang ◽  
Yaohong Suo ◽  
Juan Zhang
Keyword(s):  
Normal Form ◽  
Center Manifold ◽  
Reduction Method ◽  
Delay Model ◽  
Threshold Parameter ◽  
Normal Form Theory ◽  
Center Manifold Reduction ◽  
Form Theory ◽  
The Stability ◽  
Manifold Reduction

This paper formulates a delay model characterizing the competition between bacteria and immune system. The center manifold reduction method and the normal form theory due to Faria and Magalhaes are used to compute the normal form of the model, and the stability of two nonhyperbolic equilibria is discussed. Sensitivity analysis suggests that the growth rate of bacteria is the most sensitive parameter of the threshold parameterR0and should be targeted in the controlling strategies.

scholarly journals Resonant instability in two-dimensional vortex arrays

2010 ◽  
Vol 467 (2128) ◽  
pp. 1164-1185 ◽  
Author(s):  
Paolo Luzzatto-Fegiz ◽  
Charles H. K. Williamson
Keyword(s):  
Linear Stability ◽  
Stability Boundary ◽  
Oscillatory Instability ◽  
Two Dimensional ◽  
Complex Flows ◽  
Stability Calculation ◽  
Resonant Instability ◽  
The Stability ◽  
Stability Results ◽  
Good Agreement

We examine conditions for the development of an oscillatory instability in two-dimensional vortex arrays. By building on the theory of Krein signatures for Hamiltonian systems, and considering constraints owing to impulse conservation, we show that a resonant instability (developing through coalescence of two eigenvalues) cannot occur for one or two vortices. We illustrate this deduction by examining available linear stability results for one or two vortices. Our work indicates that a resonant instability may, however, occur for three or more vortices. For these more complex flows, we propose a simple model, based on an elliptical vortex representation, to detect the onset of an oscillatory instability. We provide an example in support of our theory by examining three co-rotating vortices, for which we also perform a linear stability analysis. The stability boundary in our model is in good agreement with the full stability calculation. In addition, we show that eigenmodes associated with an overall rotation or an overall displacement of the vortices always have eigenvalues equal to zero and ±i Ω , respectively, where Ω is the angular velocity of the array. These results, for overall rotation and displacement modes, can also be used to immediately check the accuracy of a detailed stability calculation.

Coexistence of Periodic Oscillations Induced by Predator Cannibalism in a Delayed Diffusive Predator–Prey Model

2019 ◽  
Vol 29 (07) ◽  
pp. 1950089
Author(s):  
Daifeng Duan ◽  
Ben Niu ◽  
Junjie Wei
Keyword(s):  
Hopf Bifurcation ◽  
Center Manifold ◽  
Hopf Bifurcations ◽  
Center Manifold Reduction ◽  
Periodic Oscillations ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Prey System ◽  
Predator Cannibalism ◽  
Manifold Reduction

This paper is concerned with the effect of predator cannibalism in a delayed diffusive predator–prey system. We aim for the case where the corresponding linear system has two pairs of purely imaginary eigenvalues at a critical point, leading to Hopf–Hopf bifurcation. An approach of center manifold reduction is applied to derive the normal form for such nonresonant Hopf–Hopf bifurcations. We find that the system exhibits very rich dynamics, including the coexistence of periodic and quasi-periodic oscillations. Numerically, we show that Hopf–Hopf bifurcation is induced if the strength of the predator cannibalism term belongs to an appropriate interval.

scholarly journals Complex eigenvalues for the stability of Couette flow

1984 ◽  
Vol 396 (1810) ◽  
pp. 75-94 ◽  
Keyword(s):  
Eigenvalue Problem ◽  
Linear Stability ◽  
Couette Flow ◽  
Perturbation Methods ◽  
Stability Boundary ◽  
Outer Cylinder ◽  
Concentric Cylinders ◽  
Complex Eigenvalues ◽  
The Stability ◽  
Axisymmetric Disturbances

The eigenvalue problem for the linear stability of Couette flow between rotating concentric cylinders to axisymmetric disturbances is considered. It is shown by numerical calculations and by formal perturbation methods that when the outer cylinder is at rest there exist complex eigenvalues corresponding to oscillatory damped disturbances. The structure of the first few eigenvalues in the spectrum is discussed. The results do not contradict the ‘principle of exchange of stabilities’; namely, for a fixed axial wavenumber the first mode to become unstable as the speed of the inner cylinder is increased is non-oscillatory as the stability boundary is crossed.

STABILITY AND HOPF BIFURCATIONS IN A DELAYED PREDATOR–PREY SYSTEM WITH A DISTRIBUTED DELAY

2009 ◽  
Vol 19 (07) ◽  
pp. 2283-2294 ◽  
Author(s):  
CUN-HUA ZHANG ◽  
XIANG-PING YAN
Keyword(s):  
Functional Differential Equations ◽  
Distributed Delay ◽  
Positive Equilibrium ◽  
Hopf Bifurcations ◽  
Normal Form Theory ◽  
Center Manifold Reduction ◽  
Predator Prey ◽  
Prey System ◽  
Functional Differential ◽  
The Stability

This paper is concerned with a delayed Lotka–Volterra two-species predator–prey system with a distributed delay. By linearizing the system at the positive equilibrium and analyzing the associated characteristic equation, the asymptotic stability of positive equilibrium is investigated and Hopf bifurcations are demonstrated. It is found that the positive equilibrium of the system is always locally asymptotically stable when the delay kernel is the weak kernel while there is a stability switch of positive equilibrium when the delay kernel is the strong kernel and the system can undergo a Hopf bifurcation at the positive equilibrium when the average time delay in the delay kernel crosses certain critical values. In particular, by applying the normal form theory and center manifold reduction to functional differential equations (FDEs), the explicit formula determining the direction of Hopf bifurcations and the stability of bifurcated periodic solutions is given. Finally, some numerical simulations are also included to support the analytical results obtained.

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